first step for #168, adds dart:js impl to the build

tool/sdk_expected_errors.txt

+severe: line 90, column 1 of dart:js: [Message] File dart:html not found
+import 'dart:html' show Blob, Event, ImageData, Node, Window;
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+severe: line 92, column 1 of dart:js: [Message] File dart:indexed_db not found
+import 'dart:indexed_db' show KeyRange;
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 426, column 16 of dart:math: [DownCastImplicit] rnd32.remainder(max) (num) will need runtime check to cast to type int
+      result = rnd32.remainder(max); // % max;
+               ^^^^^^^^^^^^^^^^^^^^
+warning: line 37, column 25 of dart:math/point.dart: [DownCastComposite] x + other.x (num) will need runtime check to cast to type T
+    return new Point<T>(x + other.x, y + other.y);
+                        ^^^^^^^^^^^
+warning: line 37, column 38 of dart:math/point.dart: [DownCastComposite] y + other.y (num) will need runtime check to cast to type T
+    return new Point<T>(x + other.x, y + other.y);
+                                     ^^^^^^^^^^^
+warning: line 46, column 25 of dart:math/point.dart: [DownCastComposite] x - other.x (num) will need runtime check to cast to type T
+    return new Point<T>(x - other.x, y - other.y);
+                        ^^^^^^^^^^^
+warning: line 46, column 38 of dart:math/point.dart: [DownCastComposite] y - other.y (num) will need runtime check to cast to type T
+    return new Point<T>(x - other.x, y - other.y);
+                                     ^^^^^^^^^^^
+warning: line 59, column 25 of dart:math/point.dart: [DownCastComposite] x * factor (num) will need runtime check to cast to type T
+    return new Point<T>(x * factor, y * factor);
+                        ^^^^^^^^^^
+warning: line 59, column 37 of dart:math/point.dart: [DownCastComposite] y * factor (num) will need runtime check to cast to type T
+    return new Point<T>(x * factor, y * factor);
+                                    ^^^^^^^^^^
+warning: line 86, column 12 of dart:math/point.dart: [DownCastComposite] dx * dx + dy * dy (num) will need runtime check to cast to type T
+    return dx * dx + dy * dy;
+           ^^^^^^^^^^^^^^^^^
+warning: line 33, column 18 of dart:math/rectangle.dart: [DownCastComposite] left + width (num) will need runtime check to cast to type T
+  T get right => left + width;
+                 ^^^^^^^^^^^^
+warning: line 35, column 19 of dart:math/rectangle.dart: [DownCastComposite] top + height (num) will need runtime check to cast to type T
+  T get bottom => top + height;
+                  ^^^^^^^^^^^^
+warning: line 68, column 33 of dart:math/rectangle.dart: [DownCastComposite] x0 (num) will need runtime check to cast to type T
+        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
+                                ^^
+warning: line 68, column 37 of dart:math/rectangle.dart: [DownCastComposite] y0 (num) will need runtime check to cast to type T
+        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
+                                    ^^
+warning: line 68, column 41 of dart:math/rectangle.dart: [DownCastComposite] x1 - x0 (num) will need runtime check to cast to type T
+        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
+                                        ^^^^^^^
+warning: line 68, column 50 of dart:math/rectangle.dart: [DownCastComposite] y1 - y0 (num) will need runtime check to cast to type T
+        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
+                                                 ^^^^^^^
+warning: line 95, column 29 of dart:math/rectangle.dart: [DownCastComposite] left (num) will need runtime check to cast to type T
+    return new Rectangle<T>(left, top, right - left, bottom - top);
+                            ^^^^
+warning: line 95, column 35 of dart:math/rectangle.dart: [DownCastComposite] top (num) will need runtime check to cast to type T
+    return new Rectangle<T>(left, top, right - left, bottom - top);
+                                  ^^^
+warning: line 95, column 40 of dart:math/rectangle.dart: [DownCastComposite] right - left (num) will need runtime check to cast to type T
+    return new Rectangle<T>(left, top, right - left, bottom - top);
+                                       ^^^^^^^^^^^^
+warning: line 95, column 54 of dart:math/rectangle.dart: [DownCastComposite] bottom - top (num) will need runtime check to cast to type T
+    return new Rectangle<T>(left, top, right - left, bottom - top);
+                                                     ^^^^^^^^^^^^
+warning: line 119, column 41 of dart:math/rectangle.dart: [DownCastComposite] this.left + this.width (num) will need runtime check to cast to type T
+  Point<T> get topRight => new Point<T>(this.left + this.width, this.top);
+                                        ^^^^^^^^^^^^^^^^^^^^^^
+warning: line 120, column 44 of dart:math/rectangle.dart: [DownCastComposite] this.left + this.width (num) will need runtime check to cast to type T
+  Point<T> get bottomRight => new Point<T>(this.left + this.width,
+                                           ^^^^^^^^^^^^^^^^^^^^^^
+warning: line 121, column 7 of dart:math/rectangle.dart: [DownCastComposite] this.top + this.height (num) will need runtime check to cast to type T
+      this.top + this.height);
+      ^^^^^^^^^^^^^^^^^^^^^^
+warning: line 123, column 7 of dart:math/rectangle.dart: [DownCastComposite] this.top + this.height (num) will need runtime check to cast to type T
+      this.top + this.height);
+      ^^^^^^^^^^^^^^^^^^^^^^
+warning: line 151, column 22 of dart:math/rectangle.dart: [DownCastComposite] (width < 0) ? -width * 0 : width (dynamic) will need runtime check to cast to type T
+      : this.width = (width < 0) ? -width * 0 : width,  // Inline _clampToZero.
+                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 152, column 23 of dart:math/rectangle.dart: [DownCastComposite] (height < 0) ? -height * 0 : height (dynamic) will need runtime check to cast to type T
+        this.height = (height < 0) ?  -height * 0 : height;
+                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 167, column 14 of dart:math/rectangle.dart: [DownCastComposite] min(a.x, b.x) (num) will need runtime check to cast to type T
+    T left = min(a.x, b.x);
+             ^^^^^^^^^^^^^
+warning: line 168, column 15 of dart:math/rectangle.dart: [DownCastComposite] max(a.x, b.x) - left (num) will need runtime check to cast to type T
+    T width = max(a.x, b.x) - left;
+              ^^^^^^^^^^^^^^^^^^^^
+warning: line 169, column 13 of dart:math/rectangle.dart: [DownCastComposite] min(a.y, b.y) (num) will need runtime check to cast to type T
+    T top = min(a.y, b.y);
+            ^^^^^^^^^^^^^
+warning: line 170, column 16 of dart:math/rectangle.dart: [DownCastComposite] max(a.y, b.y) - top (num) will need runtime check to cast to type T
+    T height = max(a.y, b.y) - top;
+               ^^^^^^^^^^^^^^^^^^^
+warning: line 212, column 23 of dart:math/rectangle.dart: [DownCastComposite] (width < 0) ? _clampToZero(width) : width (dynamic) will need runtime check to cast to type T
+      : this._width = (width < 0) ? _clampToZero(width) : width,
+                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 213, column 24 of dart:math/rectangle.dart: [DownCastComposite] (height < 0) ? _clampToZero(height) : height (dynamic) will need runtime check to cast to type T
+        this._height = (height < 0) ? _clampToZero(height) : height;
+                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 228, column 14 of dart:math/rectangle.dart: [DownCastComposite] min(a.x, b.x) (num) will need runtime check to cast to type T
+    T left = min(a.x, b.x);
+             ^^^^^^^^^^^^^
+warning: line 229, column 15 of dart:math/rectangle.dart: [DownCastComposite] max(a.x, b.x) - left (num) will need runtime check to cast to type T
+    T width = max(a.x, b.x) - left;
+              ^^^^^^^^^^^^^^^^^^^^
+warning: line 230, column 13 of dart:math/rectangle.dart: [DownCastComposite] min(a.y, b.y) (num) will need runtime check to cast to type T
+    T top = min(a.y, b.y);
+            ^^^^^^^^^^^^^
+warning: line 231, column 16 of dart:math/rectangle.dart: [DownCastComposite] max(a.y, b.y) - top (num) will need runtime check to cast to type T
+    T height = max(a.y, b.y) - top;
+               ^^^^^^^^^^^^^^^^^^^
+warning: line 247, column 28 of dart:math/rectangle.dart: [DownCastComposite] _clampToZero(width) (num) will need runtime check to cast to type T
+    if (width < 0) width = _clampToZero(width);
+                           ^^^^^^^^^^^^^^^^^^^
+warning: line 263, column 30 of dart:math/rectangle.dart: [DownCastComposite] _clampToZero(height) (num) will need runtime check to cast to type T
+    if (height < 0) height = _clampToZero(height);
+                             ^^^^^^^^^^^^^^^^^^^^
 warning: line 80, column 12 of dart:_interceptors/js_array.dart: [DownCastComposite] JS('var', r'#.pop()', this) (dynamic) will need runtime check to cast to type E
     return JS('var', r'#.pop()', this);
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 warning: line 125, column 9 of dart:_interceptors/js_array.dart: [DownCastComposite] JS('', '#[#]', this, i) (dynamic) will need runtime check to cast to type E
       f(JS('', '#[#]', this, i));
         ^^^^^^^^^^^^^^^^^^^^^^^
 warning: line 161, column 12 of dart:_interceptors/js_array.dart: [DownCastComposite] IterableMixinWorkaround.reduce(this, combine) (dynamic) will need runtime check to cast to type E
     return IterableMixinWorkaround.reduce(this, combine);
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 warning: line 169, column 12 of dart:_interceptors/js_array.dart: [DownCastComposite] IterableMixinWorkaround.firstWhere(this, test, orElse) (dynamic) will need runtime check to cast to type E
@@ skipping 118 matching lines @@
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 warning: line 140, column 43 of dart:_js_helper/regexp_helper.dart: [DownCastComposite] match (List<dynamic>) will need runtime check to cast to type List<String>
     return new _MatchImplementation(this, match);
                                           ^^^^^
 warning: line 152, column 43 of dart:_js_helper/regexp_helper.dart: [DownCastComposite] match (List<dynamic>) will need runtime check to cast to type List<String>
     return new _MatchImplementation(this, match);
                                           ^^^^^
 warning: line 137, column 23 of dart:_js_helper/string_helper.dart: [DownCastComposite] pattern.allMatches(receiver) (dynamic) will need runtime check to cast to type Iterable<Match>
   for (Match match in pattern.allMatches(receiver)) {
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 426, column 16 of dart:math: [DownCastImplicit] rnd32.remainder(max) (num) will need runtime check to cast to type int
-      result = rnd32.remainder(max); // % max;
-               ^^^^^^^^^^^^^^^^^^^^
-warning: line 37, column 25 of dart:math/point.dart: [DownCastComposite] x + other.x (num) will need runtime check to cast to type T
-    return new Point<T>(x + other.x, y + other.y);
-                        ^^^^^^^^^^^
-warning: line 37, column 38 of dart:math/point.dart: [DownCastComposite] y + other.y (num) will need runtime check to cast to type T
-    return new Point<T>(x + other.x, y + other.y);
-                                     ^^^^^^^^^^^
-warning: line 46, column 25 of dart:math/point.dart: [DownCastComposite] x - other.x (num) will need runtime check to cast to type T
-    return new Point<T>(x - other.x, y - other.y);
-                        ^^^^^^^^^^^
-warning: line 46, column 38 of dart:math/point.dart: [DownCastComposite] y - other.y (num) will need runtime check to cast to type T
-    return new Point<T>(x - other.x, y - other.y);
-                                     ^^^^^^^^^^^
-warning: line 59, column 25 of dart:math/point.dart: [DownCastComposite] x * factor (num) will need runtime check to cast to type T
-    return new Point<T>(x * factor, y * factor);
-                        ^^^^^^^^^^
-warning: line 59, column 37 of dart:math/point.dart: [DownCastComposite] y * factor (num) will need runtime check to cast to type T
-    return new Point<T>(x * factor, y * factor);
-                                    ^^^^^^^^^^
-warning: line 86, column 12 of dart:math/point.dart: [DownCastComposite] dx * dx + dy * dy (num) will need runtime check to cast to type T
-    return dx * dx + dy * dy;
-           ^^^^^^^^^^^^^^^^^
-warning: line 33, column 18 of dart:math/rectangle.dart: [DownCastComposite] left + width (num) will need runtime check to cast to type T
-  T get right => left + width;
-                 ^^^^^^^^^^^^
-warning: line 35, column 19 of dart:math/rectangle.dart: [DownCastComposite] top + height (num) will need runtime check to cast to type T
-  T get bottom => top + height;
-                  ^^^^^^^^^^^^
-warning: line 68, column 33 of dart:math/rectangle.dart: [DownCastComposite] x0 (num) will need runtime check to cast to type T
-        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
-                                ^^
-warning: line 68, column 37 of dart:math/rectangle.dart: [DownCastComposite] y0 (num) will need runtime check to cast to type T
-        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
-                                    ^^
-warning: line 68, column 41 of dart:math/rectangle.dart: [DownCastComposite] x1 - x0 (num) will need runtime check to cast to type T
-        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
-                                        ^^^^^^^
-warning: line 68, column 50 of dart:math/rectangle.dart: [DownCastComposite] y1 - y0 (num) will need runtime check to cast to type T
-        return new Rectangle<T>(x0, y0, x1 - x0, y1 - y0);
-                                                 ^^^^^^^
-warning: line 95, column 29 of dart:math/rectangle.dart: [DownCastComposite] left (num) will need runtime check to cast to type T
-    return new Rectangle<T>(left, top, right - left, bottom - top);
-                            ^^^^
-warning: line 95, column 35 of dart:math/rectangle.dart: [DownCastComposite] top (num) will need runtime check to cast to type T
-    return new Rectangle<T>(left, top, right - left, bottom - top);
-                                  ^^^
-warning: line 95, column 40 of dart:math/rectangle.dart: [DownCastComposite] right - left (num) will need runtime check to cast to type T
-    return new Rectangle<T>(left, top, right - left, bottom - top);
-                                       ^^^^^^^^^^^^
-warning: line 95, column 54 of dart:math/rectangle.dart: [DownCastComposite] bottom - top (num) will need runtime check to cast to type T
-    return new Rectangle<T>(left, top, right - left, bottom - top);
-                                                     ^^^^^^^^^^^^
-warning: line 119, column 41 of dart:math/rectangle.dart: [DownCastComposite] this.left + this.width (num) will need runtime check to cast to type T
-  Point<T> get topRight => new Point<T>(this.left + this.width, this.top);
-                                        ^^^^^^^^^^^^^^^^^^^^^^
-warning: line 120, column 44 of dart:math/rectangle.dart: [DownCastComposite] this.left + this.width (num) will need runtime check to cast to type T
-  Point<T> get bottomRight => new Point<T>(this.left + this.width,
-                                           ^^^^^^^^^^^^^^^^^^^^^^
-warning: line 121, column 7 of dart:math/rectangle.dart: [DownCastComposite] this.top + this.height (num) will need runtime check to cast to type T
-      this.top + this.height);
-      ^^^^^^^^^^^^^^^^^^^^^^
-warning: line 123, column 7 of dart:math/rectangle.dart: [DownCastComposite] this.top + this.height (num) will need runtime check to cast to type T
-      this.top + this.height);
-      ^^^^^^^^^^^^^^^^^^^^^^
-warning: line 151, column 22 of dart:math/rectangle.dart: [DownCastComposite] (width < 0) ? -width * 0 : width (dynamic) will need runtime check to cast to type T
-      : this.width = (width < 0) ? -width * 0 : width,  // Inline _clampToZero.
-                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 152, column 23 of dart:math/rectangle.dart: [DownCastComposite] (height < 0) ? -height * 0 : height (dynamic) will need runtime check to cast to type T
-        this.height = (height < 0) ?  -height * 0 : height;
-                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 167, column 14 of dart:math/rectangle.dart: [DownCastComposite] min(a.x, b.x) (num) will need runtime check to cast to type T
-    T left = min(a.x, b.x);
-             ^^^^^^^^^^^^^
-warning: line 168, column 15 of dart:math/rectangle.dart: [DownCastComposite] max(a.x, b.x) - left (num) will need runtime check to cast to type T
-    T width = max(a.x, b.x) - left;
-              ^^^^^^^^^^^^^^^^^^^^
-warning: line 169, column 13 of dart:math/rectangle.dart: [DownCastComposite] min(a.y, b.y) (num) will need runtime check to cast to type T
-    T top = min(a.y, b.y);
-            ^^^^^^^^^^^^^
-warning: line 170, column 16 of dart:math/rectangle.dart: [DownCastComposite] max(a.y, b.y) - top (num) will need runtime check to cast to type T
-    T height = max(a.y, b.y) - top;
-               ^^^^^^^^^^^^^^^^^^^
-warning: line 212, column 23 of dart:math/rectangle.dart: [DownCastComposite] (width < 0) ? _clampToZero(width) : width (dynamic) will need runtime check to cast to type T
-      : this._width = (width < 0) ? _clampToZero(width) : width,
-                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 213, column 24 of dart:math/rectangle.dart: [DownCastComposite] (height < 0) ? _clampToZero(height) : height (dynamic) will need runtime check to cast to type T
-        this._height = (height < 0) ? _clampToZero(height) : height;
-                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 228, column 14 of dart:math/rectangle.dart: [DownCastComposite] min(a.x, b.x) (num) will need runtime check to cast to type T
-    T left = min(a.x, b.x);
-             ^^^^^^^^^^^^^
-warning: line 229, column 15 of dart:math/rectangle.dart: [DownCastComposite] max(a.x, b.x) - left (num) will need runtime check to cast to type T
-    T width = max(a.x, b.x) - left;
-              ^^^^^^^^^^^^^^^^^^^^
-warning: line 230, column 13 of dart:math/rectangle.dart: [DownCastComposite] min(a.y, b.y) (num) will need runtime check to cast to type T
-    T top = min(a.y, b.y);
-            ^^^^^^^^^^^^^
-warning: line 231, column 16 of dart:math/rectangle.dart: [DownCastComposite] max(a.y, b.y) - top (num) will need runtime check to cast to type T
-    T height = max(a.y, b.y) - top;
-               ^^^^^^^^^^^^^^^^^^^
-warning: line 247, column 28 of dart:math/rectangle.dart: [DownCastComposite] _clampToZero(width) (num) will need runtime check to cast to type T
-    if (width < 0) width = _clampToZero(width);
-                           ^^^^^^^^^^^^^^^^^^^
-warning: line 263, column 30 of dart:math/rectangle.dart: [DownCastComposite] _clampToZero(height) (num) will need runtime check to cast to type T
-    if (height < 0) height = _clampToZero(height);
-                             ^^^^^^^^^^^^^^^^^^^^
-warning: line 310, column 12 of dart:_internal/iterable.dart: [DownCastComposite] result (List<dynamic>) will need runtime check to cast to type List<E>
-    return result;
-           ^^^^^^
-warning: line 357, column 39 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<S>
-    return new MappedIterable<S, T>._(iterable, function);
-                                      ^^^^^^^^
-warning: line 378, column 17 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<S>
-      : super._(iterable, function);
-                ^^^^^^^^
-warning: line 454, column 76 of dart:_internal/iterable.dart: [DownCastComposite] _f ((dynamic) → Iterable<dynamic>) will need runtime check to cast to type (S) → Iterable<T>
-  Iterator<T> get iterator => new ExpandIterator<S, T>(_iterable.iterator, _f);
-                                                                           ^^
-warning: line 481, column 29 of dart:_internal/iterable.dart: [DownCastComposite] _f(_iterator.current).iterator (Iterator<dynamic>) will need runtime check to cast to type Iterator<T>
-        _currentExpansion = _f(_iterator.current).iterator;
-                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 961, column 33 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<T>
-    return new WhereIterable<T>(iterable, f);
-                                ^^^^^^^^
-warning: line 961, column 43 of dart:_internal/iterable.dart: [DownCastComposite] f ((dynamic) → bool) will need runtime check to cast to type (T) → bool
-    return new WhereIterable<T>(iterable, f);
-                                          ^
-warning: line 978, column 35 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
-    return new SubListIterable<T>(list, 0, n);
-                                  ^^^^
-warning: line 983, column 37 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<T>
-    return new TakeWhileIterable<T>(iterable, test);
-                                    ^^^^^^^^
-warning: line 983, column 47 of dart:_internal/iterable.dart: [DownCastComposite] test ((dynamic) → bool) will need runtime check to cast to type (T) → bool
-    return new TakeWhileIterable<T>(iterable, test);
-                                              ^^^^
-warning: line 988, column 35 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
-    return new SubListIterable<T>(list, n, null);
-                                  ^^^^
-warning: line 993, column 37 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<T>
-    return new SkipWhileIterable<T>(iterable, test);
-                                    ^^^^^^^^
-warning: line 993, column 47 of dart:_internal/iterable.dart: [DownCastComposite] test ((dynamic) → bool) will need runtime check to cast to type (T) → bool
-    return new SkipWhileIterable<T>(iterable, test);
-                                              ^^^^
-warning: line 997, column 40 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
-    return new ReversedListIterable<T>(list);
-                                       ^^^^
-warning: line 1033, column 35 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
-    return new SubListIterable<T>(list, start, end);
-                                  ^^^^
-warning: line 1115, column 31 of dart:_internal/iterable.dart: [DownCastComposite] l (List<dynamic>) will need runtime check to cast to type List<T>
-    return new ListMapView<T>(l);
-                              ^
-warning: line 251, column 59 of dart:_internal/list.dart: [DownCastImplicit] key (Object) will need runtime check to cast to type int
-  E operator[] (Object key) => containsKey(key) ? _values[key] : null;
-                                                          ^^^
-warning: line 179, column 12 of dart:collection: [DownCastComposite] JS('var', '#.splice(#, 2)[1]', bucket, index) (dynamic) will need runtime check to cast to type V
-    return JS('var', '#.splice(#, 2)[1]', bucket, index);
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 193, column 14 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
-      action(key, this[key]);
-             ^^^
-warning: line 261, column 17 of dart:collection: [DownCastComposite] _getTableEntry(table, key) (dynamic) will need runtime check to cast to type V
-      V value = _getTableEntry(table, key);
-                ^^^^^^^^^^^^^^^^^^^^^^^^^^
-severe: line 372, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type K
-      : _validKey = (validKey != null) ? validKey : ((v) => v is K);
-                                                            ^^^^^^
-warning: line 397, column 49 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
-    return JS('int', '# & 0x3ffffff', _hashCode(key));
-                                                ^^^
-warning: line 404, column 19 of dart:collection: [DownCastComposite] JS('var', '#[#]', bucket, i) (dynamic) will need runtime check to cast to type K
-      if (_equals(JS('var', '#[#]', bucket, i), key)) return i;
-                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 404, column 49 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
-      if (_equals(JS('var', '#[#]', bucket, i), key)) return i;
-                                                ^^^
-warning: line 430, column 9 of dart:collection: [DownCastComposite] JS('var', '#[#]', keys, i) (dynamic) will need runtime check to cast to type E
-      f(JS('var', '#[#]', keys, i));
-        ^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 456, column 18 of dart:collection: [DownCastComposite] JS('var', '#[#]', keys, offset) (dynamic) will need runtime check to cast to type E
-      _current = JS('var', '#[#]', keys, offset);
-                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 561, column 12 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
-    return cell._value;
-           ^^^^^^^^^^^
-warning: line 627, column 12 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
-    return cell._value;
-           ^^^^^^^^^^^
-warning: line 642, column 14 of dart:collection: [DownCastComposite] cell._key (dynamic) will need runtime check to cast to type K
-      action(cell._key, cell._value);
-             ^^^^^^^^^
-warning: line 642, column 25 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
-      action(cell._key, cell._value);
-                        ^^^^^^^^^^^
-warning: line 665, column 12 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
-    return cell._value;
-           ^^^^^^^^^^^
-severe: line 795, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type K
-      : _validKey = (validKey != null) ? validKey : ((v) => v is K);
-                                                            ^^^^^^
-warning: line 820, column 49 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
-    return JS('int', '# & 0x3ffffff', _hashCode(key));
-                                                ^^^
-warning: line 828, column 19 of dart:collection: [DownCastComposite] cell._key (dynamic) will need runtime check to cast to type K
-      if (_equals(cell._key, key)) return i;
-                  ^^^^^^^^^
-warning: line 828, column 30 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
-      if (_equals(cell._key, key)) return i;
-                             ^^^
-warning: line 862, column 9 of dart:collection: [DownCastComposite] cell._key (dynamic) will need runtime check to cast to type E
-      f(cell._key);
-        ^^^^^^^^^
-warning: line 889, column 18 of dart:collection: [DownCastComposite] _cell._key (dynamic) will need runtime check to cast to type E
-      _current = _cell._key;
-                 ^^^^^^^^^^
-warning: line 951, column 14 of dart:collection: [DownCastComposite] this.contains(object) ? object : null (Object) will need runtime check to cast to type E
-      return this.contains(object) ? object : null;
-             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 962, column 12 of dart:collection: [DownCastComposite] bucket[index] (dynamic) will need runtime check to cast to type E
-    return bucket[index];
-           ^^^^^^^^^^^^^
-severe: line 1194, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type E
-      : _validKey = (validKey != null) ? validKey : ((x) => x is E);
-                                                            ^^^^^^
-warning: line 1202, column 21 of dart:collection: [DownCastComposite] JS('var', '#[#]', bucket, i) (dynamic) will need runtime check to cast to type E
-      if (_equality(JS('var', '#[#]', bucket, i), element)) return i;
-                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 1202, column 51 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
-      if (_equality(JS('var', '#[#]', bucket, i), element)) return i;
-                                                  ^^^^^^^
-warning: line 1212, column 47 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
-    return JS('int', '# & 0x3ffffff', _hasher(element));
-                                              ^^^^^^^
-warning: line 1251, column 18 of dart:collection: [DownCastComposite] JS('var', '#[#]', elements, offset) (dynamic) will need runtime check to cast to type E
-      _current = JS('var', '#[#]', elements, offset);
-                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 1328, column 14 of dart:collection: [DownCastComposite] this.contains(object) ? object : null (Object) will need runtime check to cast to type E
-      return this.contains(object) ? object : null;
-             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 1340, column 12 of dart:collection: [DownCastComposite] bucket[index]._element (dynamic) will need runtime check to cast to type E
-    return bucket[index]._element;
-           ^^^^^^^^^^^^^^^^^^^^^^
-warning: line 1347, column 14 of dart:collection: [DownCastComposite] cell._element (dynamic) will need runtime check to cast to type E
-      action(cell._element);
-             ^^^^^^^^^^^^^
-warning: line 1357, column 12 of dart:collection: [DownCastComposite] _first._element (dynamic) will need runtime check to cast to type E
-    return _first._element;
-           ^^^^^^^^^^^^^^^
-warning: line 1362, column 12 of dart:collection: [DownCastComposite] _last._element (dynamic) will need runtime check to cast to type E
-    return _last._element;
-           ^^^^^^^^^^^^^^
-warning: line 1431, column 19 of dart:collection: [DownCastComposite] cell._element (dynamic) will need runtime check to cast to type E
-      E element = cell._element;
-                  ^^^^^^^^^^^^^
-severe: line 1596, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type E
-      : _validKey = (validKey != null) ? validKey : ((x) => x is E);
-                                                            ^^^^^^
-warning: line 1606, column 21 of dart:collection: [DownCastComposite] cell._element (dynamic) will need runtime check to cast to type E
-      if (_equality(cell._element, element)) return i;
-                    ^^^^^^^^^^^^^
-warning: line 1606, column 36 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
-      if (_equality(cell._element, element)) return i;
-                                   ^^^^^^^
-warning: line 1616, column 47 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
-    return JS('int', '# & 0x3ffffff', _hasher(element));
-                                              ^^^^^^^
-warning: line 1678, column 18 of dart:collection: [DownCastComposite] _cell._element (dynamic) will need runtime check to cast to type E
-      _current = _cell._element;
-                 ^^^^^^^^^^^^^^
-warning: line 112, column 40 of dart:collection/hash_map.dart: [DownCastComposite] v (dynamic) will need runtime check to cast to type V
-    other.forEach((k, v) { result[k] = v; });
-                                       ^
-warning: line 112, column 35 of dart:collection/hash_map.dart: [DownCastComposite] k (dynamic) will need runtime check to cast to type K
-    other.forEach((k, v) { result[k] = v; });
-                                  ^
-warning: line 128, column 17 of dart:collection/hash_set.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
-    for (E e in elements) result.add(e);
-                ^^^^^^^^
-warning: line 33, column 16 of dart:collection/iterator.dart: [DownCastComposite] _iterator.current (dynamic) will need runtime check to cast to type E
-    E result = _iterator.current;
-               ^^^^^^^^^^^^^^^^^
-warning: line 99, column 40 of dart:collection/linked_hash_map.dart: [DownCastComposite] v (dynamic) will need runtime check to cast to type V
-    other.forEach((k, v) { result[k] = v; });
-                                       ^
-warning: line 99, column 35 of dart:collection/linked_hash_map.dart: [DownCastComposite] k (dynamic) will need runtime check to cast to type K
-    other.forEach((k, v) { result[k] = v; });
-                                  ^
-warning: line 142, column 12 of dart:collection/linked_hash_map.dart: [DownCastComposite] fillLiteralMap(keyValuePairs, new _LinkedHashMap<K, V>()) (dynamic) will need runtime check to cast to type LinkedHashMap<K, V>
-    return fillLiteralMap(keyValuePairs, new _LinkedHashMap<K, V>());
-           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 65, column 56 of dart:collection/linked_list.dart: [DownCastComposite] entry (dynamic) will need runtime check to cast to type E
-    entries.forEach((entry) => _insertAfter(_previous, entry));
-                                                       ^^^^^
-warning: line 93, column 17 of dart:collection/linked_list.dart: [DownCastComposite] next (_LinkedListLink) will need runtime check to cast to type E
-      E entry = next;
-                ^^^^
-warning: line 105, column 12 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
-    return _next;
-           ^^^^^
-warning: line 112, column 12 of dart:collection/linked_list.dart: [DownCastComposite] _previous (_LinkedListLink) will need runtime check to cast to type E
-    return _previous;
-           ^^^^^^^^^
-warning: line 122, column 12 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
-    return _next;
-           ^^^^^
-warning: line 134, column 14 of dart:collection/linked_list.dart: [DownCastComposite] current (_LinkedListLink) will need runtime check to cast to type E
-      action(current);
-             ^^^^^^^
-warning: line 192, column 16 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
-    _current = _next;
-               ^^^^^
-warning: line 249, column 16 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
-    E result = _next;
-               ^^^^^
-warning: line 365, column 19 of dart:collection/list.dart: [DownCastImplicit] iterable (Iterable<E>) will need runtime check to cast to type List<dynamic>
-      otherList = iterable;
-                  ^^^^^^^^
-warning: line 377, column 27 of dart:collection/list.dart: [DownCastComposite] otherList[otherStart + i] (dynamic) will need runtime check to cast to type E
-        this[start + i] = otherList[otherStart + i];
-                          ^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 381, column 27 of dart:collection/list.dart: [DownCastComposite] otherList[otherStart + i] (dynamic) will need runtime check to cast to type E
-        this[start + i] = otherList[otherStart + i];
-                          ^^^^^^^^^^^^^^^^^^^^^^^^^
-warning: line 122, column 18 of dart:collection/maps.dart: [DownCastComposite] _map[_map.keys.first] (dynamic) will need runtime check to cast to type V
-  V get first => _map[_map.keys.first];
-                 ^^^^^^^^^^^^^^^^^^^^^
-warning: line 123, column 19 of dart:collection/maps.dart: [DownCastComposite] _map[_map.keys.single] (dynamic) will need runtime check to cast to type V
-  V get single => _map[_map.keys.single];
-                  ^^^^^^^^^^^^^^^^^^^^^^
-warning: line 124, column 17 of dart:collection/maps.dart: [DownCastComposite] _map[_map.keys.last] (dynamic) will need runtime check to cast to type V
-  V get last => _map[_map.keys.last];
-                ^^^^^^^^^^^^^^^^^^^^
-warning: line 144, column 18 of dart:collection/maps.dart: [DownCastComposite] _map[_keys.current] (dynamic) will need runtime check to cast to type V
-      _current = _map[_keys.current];
-                 ^^^^^^^^^^^^^^^^^^^
-warning: line 208, column 23 of dart:collection/queue.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
-    for (final E e in elements) {
-                      ^^^^^^^^
-warning: line 211, column 12 of dart:collection/queue.dart: [DownCastComposite] list (Queue<E>) will need runtime check to cast to type DoubleLinkedQueue<E>
-    return list;
-           ^^^^
-warning: line 402, column 40 of dart:collection/queue.dart: [DownCastComposite] sourceList (List<dynamic>) will need runtime check to cast to type Iterable<E>
-      queue._table.setRange(0, length, sourceList, 0);
-                                       ^^^^^^^^^^
-warning: line 411, column 31 of dart:collection/queue.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
-      for (final E element in elements) {
-                              ^^^^^^^^
-warning: line 480, column 52 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
-        _table.setRange(length, length + addCount, list, 0);
-                                                   ^^^^
-warning: line 486, column 52 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
-          _table.setRange(_tail, _tail + addCount, list, 0);
-                                                   ^^^^
-warning: line 490, column 52 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
-          _table.setRange(_tail, _tail + endSpace, list, 0);
-                                                   ^^^^
-warning: line 491, column 40 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
-          _table.setRange(0, preSpace, list, endSpace);
-                                       ^^^^
-warning: line 738, column 16 of dart:collection/queue.dart: [DownCastComposite] _queue._table[_position] (dynamic) will need runtime check to cast to type E
-    _current = _queue._table[_position];
-               ^^^^^^^^^^^^^^^^^^^^^^^^
-severe: line 610, column 60 of dart:collection/splay_tree.dart: [AnalyzerError] The getter '_validKey' is not defined for the class '_SplayTree<K>'
-        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
-                                                           ^^^^^^^^^
-severe: line 610, column 38 of dart:collection/splay_tree.dart: [AnalyzerError] The getter '_comparator' is not defined for the class '_SplayTree<K>'
-        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
-                                     ^^^^^^^^^^^
-warning: line 151, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] current (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeNode<K>
-    return current;
-           ^^^^^^^
-warning: line 167, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] current (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeNode<K>
-    return current;
-           ^^^^^^^
-warning: line 265, column 23 of dart:collection/splay_tree.dart: [DownCastComposite] (compare == null) ? Comparable.compare : compare (dynamic) will need runtime check to cast to type (K, K) → int
-      : _comparator = (compare == null) ? Comparable.compare : compare,
-                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-severe: line 266, column 65 of dart:collection/splay_tree.dart: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type K
-        _validKey = (isValidKey != null) ? isValidKey : ((v) => v is K);
-                                                                ^^^^^^
-warning: line 275, column 40 of dart:collection/splay_tree.dart: [DownCastComposite] v (dynamic) will need runtime check to cast to type V
-    other.forEach((k, v) { result[k] = v; });
-                                       ^
-warning: line 275, column 35 of dart:collection/splay_tree.dart: [DownCastComposite] k (dynamic) will need runtime check to cast to type K
-    other.forEach((k, v) { result[k] = v; });
-                                  ^
-warning: line 328, column 25 of dart:collection/splay_tree.dart: [DownCastComposite] key (Object) will need runtime check to cast to type K
-      int comp = _splay(key);
-                        ^^^
-warning: line 331, column 16 of dart:collection/splay_tree.dart: [DownCastComposite] mapRoot.value (dynamic) will need runtime check to cast to type V
-        return mapRoot.value;
-               ^^^^^^^^^^^^^
-warning: line 339, column 41 of dart:collection/splay_tree.dart: [DownCastComposite] key (Object) will need runtime check to cast to type K
-    _SplayTreeMapNode mapRoot = _remove(key);
-                                        ^^^
-warning: line 340, column 33 of dart:collection/splay_tree.dart: [DownCastComposite] mapRoot.value (dynamic) will need runtime check to cast to type V
-    if (mapRoot != null) return mapRoot.value;
-                                ^^^^^^^^^^^^^
-warning: line 363, column 14 of dart:collection/splay_tree.dart: [DownCastComposite] mapRoot.value (dynamic) will need runtime check to cast to type V
-      return mapRoot.value;
-             ^^^^^^^^^^^^^
-warning: line 394, column 38 of dart:collection/splay_tree.dart: [DownCastComposite] nodes.current (_SplayTreeNode<K>) will need runtime check to cast to type _SplayTreeMapNode<K, V>
-      _SplayTreeMapNode<K, V> node = nodes.current;
-                                     ^^^^^^^^^^^^^
-warning: line 408, column 37 of dart:collection/splay_tree.dart: [DownCastComposite] key (Object) will need runtime check to cast to type K
-    return _validKey(key) && _splay(key) == 0;
-                                    ^^^
-warning: line 420, column 41 of dart:collection/splay_tree.dart: [DownCastImplicit] node.right (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
-        if (node.right != null && visit(node.right)) return true;
-                                        ^^^^^^^^^^
-warning: line 421, column 16 of dart:collection/splay_tree.dart: [DownCastImplicit] node.left (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
-        node = node.left;
-               ^^^^^^^^^
-warning: line 425, column 18 of dart:collection/splay_tree.dart: [DownCastImplicit] _root (_SplayTreeNode<K>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
-    return visit(_root);
-                 ^^^^^
-warning: line 441, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _first.key (dynamic) will need runtime check to cast to type K
-    return _first.key;
-           ^^^^^^^^^^
-warning: line 449, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _last.key (dynamic) will need runtime check to cast to type K
-    return _last.key;
-           ^^^^^^^^^
-warning: line 545, column 22 of dart:collection/splay_tree.dart: [DownCastImplicit] _currentNode (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
-    return _getValue(_currentNode);
-                     ^^^^^^^^^^^^
-warning: line 610, column 29 of dart:collection/splay_tree.dart: [DownCastComposite] setOrMap._comparator (dynamic) will need runtime check to cast to type (K, K) → int
-        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
-                            ^^^^^^^^^^^^^^^^^^^^
-warning: line 610, column 51 of dart:collection/splay_tree.dart: [DownCastComposite] setOrMap._validKey (dynamic) will need runtime check to cast to type (Object) → bool
-        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
-                                                  ^^^^^^^^^^^^^^^^^^
-warning: line 628, column 39 of dart:collection/splay_tree.dart: [DownCastComposite] node.key (dynamic) will need runtime check to cast to type K
-  K _getValue(_SplayTreeNode node) => node.key;
-                                      ^^^^^^^^
-warning: line 633, column 42 of dart:collection/splay_tree.dart: [DownCastComposite] node.value (dynamic) will need runtime check to cast to type V
-  V _getValue(_SplayTreeMapNode node) => node.value;
-                                         ^^^^^^^^^^
-warning: line 641, column 55 of dart:collection/splay_tree.dart: [DownCastComposite] node (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeNode<K>
-  _SplayTreeNode<K> _getValue(_SplayTreeNode node) => node;
-                                                      ^^^^
-warning: line 691, column 23 of dart:collection/splay_tree.dart: [DownCastComposite] (compare == null) ? Comparable.compare : compare (dynamic) will need runtime check to cast to type (E, E) → int
-      : _comparator = (compare == null) ? Comparable.compare : compare,
-                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-severe: line 692, column 65 of dart:collection/splay_tree.dart: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type E
-        _validKey = (isValidKey != null) ? isValidKey : ((v) => v is E);
-                                                                ^^^^^^
-warning: line 705, column 29 of dart:collection/splay_tree.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
-    for (final E element in elements) {
-                            ^^^^^^^^
-warning: line 723, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _first.key (dynamic) will need runtime check to cast to type E
-    return _first.key;
-           ^^^^^^^^^^
-warning: line 728, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _last.key (dynamic) will need runtime check to cast to type E
-    return _last.key;
-           ^^^^^^^^^
-warning: line 739, column 40 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
-    return _validKey(object) && _splay(object) == 0;
-                                       ^^^^^^
-warning: line 751, column 20 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
-    return _remove(object) != null;
-                   ^^^^^^
-warning: line 765, column 39 of dart:collection/splay_tree.dart: [DownCastComposite] element (Object) will need runtime check to cast to type E
-      if (_validKey(element)) _remove(element);
-                                      ^^^^^^^
-warning: line 779, column 39 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
-      if (_validKey(object) && _splay(object) == 0) retainSet.add(_root.key);
-                                      ^^^^^^
-warning: line 791, column 23 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
-    int comp = _splay(object);
-                      ^^^^^^
 warning: line 168, column 14 of dart:isolate: [DownCastComposite] IsolateNatives.spawnFunction(entryPoint, message, paused).then((msg) => new Isolate(msg[1], pauseCapability: msg[2], terminateCapability: msg[3])) (Future<dynamic>) will need runtime check to cast to type Future<Isolate>
       return IsolateNatives.spawnFunction(entryPoint, message, paused)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 warning: line 234, column 14 of dart:isolate: [DownCastComposite] IsolateNatives.spawnUri(uri, args, message, paused).then((msg) => new Isolate(msg[1], pauseCapability: msg[2], terminateCapability: msg[3])) (Future<dynamic>) will need runtime check to cast to type Future<Isolate>
       return IsolateNatives.spawnUri(uri, args, message, paused)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 severe: line 452, column 28 of dart:_native_typed_data: [AnalyzerError] The getter 'length' is not defined for the class 'NativeTypedData'
         if (length == list.length) {
                            ^^^^^^
 warning: line 201, column 9 of dart:_native_typed_data: [DownCastImplicit] _storage.sublist(start * 4, end * 4) (List<double>) will need runtime check to cast to type NativeFloat32List
@@ skipping 445 matching lines @@
                       ^^^^^^^^^^^^^^^^
 warning: line 1869, column 12 of dart:core/uri.dart: [DownCastComposite] query.split("&").fold({}, (map, element) {int index = element.indexOf("="); if (index == -1) {if (element != "") {map[decodeQueryComponent(element, encoding: encoding)] = "";}} else if (index != 0) {var key = element.substring(0, index); var value = element.substring(index + 1); map[Uri.decodeQueryComponent(key, encoding: encoding)] = decodeQueryComponent(value, encoding: encoding);} return map;}) (dynamic) will need runtime check to cast to type Map<String, String>
     return query.split("&").fold({}, (map, element) {
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 warning: line 1901, column 12 of dart:core/uri.dart: [DownCastComposite] bytes.map((byteString) {int byte = int.parse(byteString); if (byte < 0 || byte > 255) {error('each part must be in the range of `0..255`');} return byte;}).toList() (List<dynamic>) will need runtime check to cast to type List<int>
     return bytes
            ^^^^^^
 warning: line 2023, column 12 of dart:core/uri.dart: [DownCastComposite] bytes (List<dynamic>) will need runtime check to cast to type List<int>
     return bytes;
            ^^^^^
+warning: line 310, column 12 of dart:_internal/iterable.dart: [DownCastComposite] result (List<dynamic>) will need runtime check to cast to type List<E>
+    return result;
+           ^^^^^^
+warning: line 357, column 39 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<S>
+    return new MappedIterable<S, T>._(iterable, function);
+                                      ^^^^^^^^
+warning: line 378, column 17 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<S>
+      : super._(iterable, function);
+                ^^^^^^^^
+warning: line 454, column 76 of dart:_internal/iterable.dart: [DownCastComposite] _f ((dynamic) → Iterable<dynamic>) will need runtime check to cast to type (S) → Iterable<T>
+  Iterator<T> get iterator => new ExpandIterator<S, T>(_iterable.iterator, _f);
+                                                                           ^^
+warning: line 481, column 29 of dart:_internal/iterable.dart: [DownCastComposite] _f(_iterator.current).iterator (Iterator<dynamic>) will need runtime check to cast to type Iterator<T>
+        _currentExpansion = _f(_iterator.current).iterator;
+                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 961, column 33 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<T>
+    return new WhereIterable<T>(iterable, f);
+                                ^^^^^^^^
+warning: line 961, column 43 of dart:_internal/iterable.dart: [DownCastComposite] f ((dynamic) → bool) will need runtime check to cast to type (T) → bool
+    return new WhereIterable<T>(iterable, f);
+                                          ^
+warning: line 978, column 35 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
+    return new SubListIterable<T>(list, 0, n);
+                                  ^^^^
+warning: line 983, column 37 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<T>
+    return new TakeWhileIterable<T>(iterable, test);
+                                    ^^^^^^^^
+warning: line 983, column 47 of dart:_internal/iterable.dart: [DownCastComposite] test ((dynamic) → bool) will need runtime check to cast to type (T) → bool
+    return new TakeWhileIterable<T>(iterable, test);
+                                              ^^^^
+warning: line 988, column 35 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
+    return new SubListIterable<T>(list, n, null);
+                                  ^^^^
+warning: line 993, column 37 of dart:_internal/iterable.dart: [DownCastComposite] iterable (Iterable<dynamic>) will need runtime check to cast to type Iterable<T>
+    return new SkipWhileIterable<T>(iterable, test);
+                                    ^^^^^^^^
+warning: line 993, column 47 of dart:_internal/iterable.dart: [DownCastComposite] test ((dynamic) → bool) will need runtime check to cast to type (T) → bool
+    return new SkipWhileIterable<T>(iterable, test);
+                                              ^^^^
+warning: line 997, column 40 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
+    return new ReversedListIterable<T>(list);
+                                       ^^^^
+warning: line 1033, column 35 of dart:_internal/iterable.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<T>
+    return new SubListIterable<T>(list, start, end);
+                                  ^^^^
+warning: line 1115, column 31 of dart:_internal/iterable.dart: [DownCastComposite] l (List<dynamic>) will need runtime check to cast to type List<T>
+    return new ListMapView<T>(l);
+                              ^
+warning: line 251, column 59 of dart:_internal/list.dart: [DownCastImplicit] key (Object) will need runtime check to cast to type int
+  E operator[] (Object key) => containsKey(key) ? _values[key] : null;
+                                                          ^^^
+warning: line 179, column 12 of dart:collection: [DownCastComposite] JS('var', '#.splice(#, 2)[1]', bucket, index) (dynamic) will need runtime check to cast to type V
+    return JS('var', '#.splice(#, 2)[1]', bucket, index);
+           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 193, column 14 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
+      action(key, this[key]);
+             ^^^
+warning: line 261, column 17 of dart:collection: [DownCastComposite] _getTableEntry(table, key) (dynamic) will need runtime check to cast to type V
+      V value = _getTableEntry(table, key);
+                ^^^^^^^^^^^^^^^^^^^^^^^^^^
+severe: line 372, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type K
+      : _validKey = (validKey != null) ? validKey : ((v) => v is K);
+                                                            ^^^^^^
+warning: line 397, column 49 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
+    return JS('int', '# & 0x3ffffff', _hashCode(key));
+                                                ^^^
+warning: line 404, column 19 of dart:collection: [DownCastComposite] JS('var', '#[#]', bucket, i) (dynamic) will need runtime check to cast to type K
+      if (_equals(JS('var', '#[#]', bucket, i), key)) return i;
+                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 404, column 49 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
+      if (_equals(JS('var', '#[#]', bucket, i), key)) return i;
+                                                ^^^
+warning: line 430, column 9 of dart:collection: [DownCastComposite] JS('var', '#[#]', keys, i) (dynamic) will need runtime check to cast to type E
+      f(JS('var', '#[#]', keys, i));
+        ^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 456, column 18 of dart:collection: [DownCastComposite] JS('var', '#[#]', keys, offset) (dynamic) will need runtime check to cast to type E
+      _current = JS('var', '#[#]', keys, offset);
+                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 561, column 12 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
+    return cell._value;
+           ^^^^^^^^^^^
+warning: line 627, column 12 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
+    return cell._value;
+           ^^^^^^^^^^^
+warning: line 642, column 14 of dart:collection: [DownCastComposite] cell._key (dynamic) will need runtime check to cast to type K
+      action(cell._key, cell._value);
+             ^^^^^^^^^
+warning: line 642, column 25 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
+      action(cell._key, cell._value);
+                        ^^^^^^^^^^^
+warning: line 665, column 12 of dart:collection: [DownCastComposite] cell._value (dynamic) will need runtime check to cast to type V
+    return cell._value;
+           ^^^^^^^^^^^
+severe: line 795, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type K
+      : _validKey = (validKey != null) ? validKey : ((v) => v is K);
+                                                            ^^^^^^
+warning: line 820, column 49 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
+    return JS('int', '# & 0x3ffffff', _hashCode(key));
+                                                ^^^
+warning: line 828, column 19 of dart:collection: [DownCastComposite] cell._key (dynamic) will need runtime check to cast to type K
+      if (_equals(cell._key, key)) return i;
+                  ^^^^^^^^^
+warning: line 828, column 30 of dart:collection: [DownCastComposite] key (dynamic) will need runtime check to cast to type K
+      if (_equals(cell._key, key)) return i;
+                             ^^^
+warning: line 862, column 9 of dart:collection: [DownCastComposite] cell._key (dynamic) will need runtime check to cast to type E
+      f(cell._key);
+        ^^^^^^^^^
+warning: line 889, column 18 of dart:collection: [DownCastComposite] _cell._key (dynamic) will need runtime check to cast to type E
+      _current = _cell._key;
+                 ^^^^^^^^^^
+warning: line 951, column 14 of dart:collection: [DownCastComposite] this.contains(object) ? object : null (Object) will need runtime check to cast to type E
+      return this.contains(object) ? object : null;
+             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 962, column 12 of dart:collection: [DownCastComposite] bucket[index] (dynamic) will need runtime check to cast to type E
+    return bucket[index];
+           ^^^^^^^^^^^^^
+severe: line 1194, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type E
+      : _validKey = (validKey != null) ? validKey : ((x) => x is E);
+                                                            ^^^^^^
+warning: line 1202, column 21 of dart:collection: [DownCastComposite] JS('var', '#[#]', bucket, i) (dynamic) will need runtime check to cast to type E
+      if (_equality(JS('var', '#[#]', bucket, i), element)) return i;
+                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 1202, column 51 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
+      if (_equality(JS('var', '#[#]', bucket, i), element)) return i;
+                                                  ^^^^^^^
+warning: line 1212, column 47 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
+    return JS('int', '# & 0x3ffffff', _hasher(element));
+                                              ^^^^^^^
+warning: line 1251, column 18 of dart:collection: [DownCastComposite] JS('var', '#[#]', elements, offset) (dynamic) will need runtime check to cast to type E
+      _current = JS('var', '#[#]', elements, offset);
+                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 1328, column 14 of dart:collection: [DownCastComposite] this.contains(object) ? object : null (Object) will need runtime check to cast to type E
+      return this.contains(object) ? object : null;
+             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 1340, column 12 of dart:collection: [DownCastComposite] bucket[index]._element (dynamic) will need runtime check to cast to type E
+    return bucket[index]._element;
+           ^^^^^^^^^^^^^^^^^^^^^^
+warning: line 1347, column 14 of dart:collection: [DownCastComposite] cell._element (dynamic) will need runtime check to cast to type E
+      action(cell._element);
+             ^^^^^^^^^^^^^
+warning: line 1357, column 12 of dart:collection: [DownCastComposite] _first._element (dynamic) will need runtime check to cast to type E
+    return _first._element;
+           ^^^^^^^^^^^^^^^
+warning: line 1362, column 12 of dart:collection: [DownCastComposite] _last._element (dynamic) will need runtime check to cast to type E
+    return _last._element;
+           ^^^^^^^^^^^^^^
+warning: line 1431, column 19 of dart:collection: [DownCastComposite] cell._element (dynamic) will need runtime check to cast to type E
+      E element = cell._element;
+                  ^^^^^^^^^^^^^
+severe: line 1596, column 61 of dart:collection: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type E
+      : _validKey = (validKey != null) ? validKey : ((x) => x is E);
+                                                            ^^^^^^
+warning: line 1606, column 21 of dart:collection: [DownCastComposite] cell._element (dynamic) will need runtime check to cast to type E
+      if (_equality(cell._element, element)) return i;
+                    ^^^^^^^^^^^^^
+warning: line 1606, column 36 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
+      if (_equality(cell._element, element)) return i;
+                                   ^^^^^^^
+warning: line 1616, column 47 of dart:collection: [DownCastComposite] element (dynamic) will need runtime check to cast to type E
+    return JS('int', '# & 0x3ffffff', _hasher(element));
+                                              ^^^^^^^
+warning: line 1678, column 18 of dart:collection: [DownCastComposite] _cell._element (dynamic) will need runtime check to cast to type E
+      _current = _cell._element;
+                 ^^^^^^^^^^^^^^
+warning: line 112, column 40 of dart:collection/hash_map.dart: [DownCastComposite] v (dynamic) will need runtime check to cast to type V
+    other.forEach((k, v) { result[k] = v; });
+                                       ^
+warning: line 112, column 35 of dart:collection/hash_map.dart: [DownCastComposite] k (dynamic) will need runtime check to cast to type K
+    other.forEach((k, v) { result[k] = v; });
+                                  ^
+warning: line 128, column 17 of dart:collection/hash_set.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
+    for (E e in elements) result.add(e);
+                ^^^^^^^^
+warning: line 33, column 16 of dart:collection/iterator.dart: [DownCastComposite] _iterator.current (dynamic) will need runtime check to cast to type E
+    E result = _iterator.current;
+               ^^^^^^^^^^^^^^^^^
+warning: line 99, column 40 of dart:collection/linked_hash_map.dart: [DownCastComposite] v (dynamic) will need runtime check to cast to type V
+    other.forEach((k, v) { result[k] = v; });
+                                       ^
+warning: line 99, column 35 of dart:collection/linked_hash_map.dart: [DownCastComposite] k (dynamic) will need runtime check to cast to type K
+    other.forEach((k, v) { result[k] = v; });
+                                  ^
+warning: line 142, column 12 of dart:collection/linked_hash_map.dart: [DownCastComposite] fillLiteralMap(keyValuePairs, new _LinkedHashMap<K, V>()) (dynamic) will need runtime check to cast to type LinkedHashMap<K, V>
+    return fillLiteralMap(keyValuePairs, new _LinkedHashMap<K, V>());
+           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 65, column 56 of dart:collection/linked_list.dart: [DownCastComposite] entry (dynamic) will need runtime check to cast to type E
+    entries.forEach((entry) => _insertAfter(_previous, entry));
+                                                       ^^^^^
+warning: line 93, column 17 of dart:collection/linked_list.dart: [DownCastComposite] next (_LinkedListLink) will need runtime check to cast to type E
+      E entry = next;
+                ^^^^
+warning: line 105, column 12 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
+    return _next;
+           ^^^^^
+warning: line 112, column 12 of dart:collection/linked_list.dart: [DownCastComposite] _previous (_LinkedListLink) will need runtime check to cast to type E
+    return _previous;
+           ^^^^^^^^^
+warning: line 122, column 12 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
+    return _next;
+           ^^^^^
+warning: line 134, column 14 of dart:collection/linked_list.dart: [DownCastComposite] current (_LinkedListLink) will need runtime check to cast to type E
+      action(current);
+             ^^^^^^^
+warning: line 192, column 16 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
+    _current = _next;
+               ^^^^^
+warning: line 249, column 16 of dart:collection/linked_list.dart: [DownCastComposite] _next (_LinkedListLink) will need runtime check to cast to type E
+    E result = _next;
+               ^^^^^
+warning: line 365, column 19 of dart:collection/list.dart: [DownCastImplicit] iterable (Iterable<E>) will need runtime check to cast to type List<dynamic>
+      otherList = iterable;
+                  ^^^^^^^^
+warning: line 377, column 27 of dart:collection/list.dart: [DownCastComposite] otherList[otherStart + i] (dynamic) will need runtime check to cast to type E
+        this[start + i] = otherList[otherStart + i];
+                          ^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 381, column 27 of dart:collection/list.dart: [DownCastComposite] otherList[otherStart + i] (dynamic) will need runtime check to cast to type E
+        this[start + i] = otherList[otherStart + i];
+                          ^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 122, column 18 of dart:collection/maps.dart: [DownCastComposite] _map[_map.keys.first] (dynamic) will need runtime check to cast to type V
+  V get first => _map[_map.keys.first];
+                 ^^^^^^^^^^^^^^^^^^^^^
+warning: line 123, column 19 of dart:collection/maps.dart: [DownCastComposite] _map[_map.keys.single] (dynamic) will need runtime check to cast to type V
+  V get single => _map[_map.keys.single];
+                  ^^^^^^^^^^^^^^^^^^^^^^
+warning: line 124, column 17 of dart:collection/maps.dart: [DownCastComposite] _map[_map.keys.last] (dynamic) will need runtime check to cast to type V
+  V get last => _map[_map.keys.last];
+                ^^^^^^^^^^^^^^^^^^^^
+warning: line 144, column 18 of dart:collection/maps.dart: [DownCastComposite] _map[_keys.current] (dynamic) will need runtime check to cast to type V
+      _current = _map[_keys.current];
+                 ^^^^^^^^^^^^^^^^^^^
+warning: line 208, column 23 of dart:collection/queue.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
+    for (final E e in elements) {
+                      ^^^^^^^^
+warning: line 211, column 12 of dart:collection/queue.dart: [DownCastComposite] list (Queue<E>) will need runtime check to cast to type DoubleLinkedQueue<E>
+    return list;
+           ^^^^
+warning: line 402, column 40 of dart:collection/queue.dart: [DownCastComposite] sourceList (List<dynamic>) will need runtime check to cast to type Iterable<E>
+      queue._table.setRange(0, length, sourceList, 0);
+                                       ^^^^^^^^^^
+warning: line 411, column 31 of dart:collection/queue.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
+      for (final E element in elements) {
+                              ^^^^^^^^
+warning: line 480, column 52 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
+        _table.setRange(length, length + addCount, list, 0);
+                                                   ^^^^
+warning: line 486, column 52 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
+          _table.setRange(_tail, _tail + addCount, list, 0);
+                                                   ^^^^
+warning: line 490, column 52 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
+          _table.setRange(_tail, _tail + endSpace, list, 0);
+                                                   ^^^^
+warning: line 491, column 40 of dart:collection/queue.dart: [DownCastComposite] list (List<dynamic>) will need runtime check to cast to type Iterable<E>
+          _table.setRange(0, preSpace, list, endSpace);
+                                       ^^^^
+warning: line 738, column 16 of dart:collection/queue.dart: [DownCastComposite] _queue._table[_position] (dynamic) will need runtime check to cast to type E
+    _current = _queue._table[_position];
+               ^^^^^^^^^^^^^^^^^^^^^^^^
+severe: line 610, column 60 of dart:collection/splay_tree.dart: [AnalyzerError] The getter '_validKey' is not defined for the class '_SplayTree<K>'
+        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
+                                                           ^^^^^^^^^
+severe: line 610, column 38 of dart:collection/splay_tree.dart: [AnalyzerError] The getter '_comparator' is not defined for the class '_SplayTree<K>'
+        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
+                                     ^^^^^^^^^^^
+warning: line 151, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] current (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeNode<K>
+    return current;
+           ^^^^^^^
+warning: line 167, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] current (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeNode<K>
+    return current;
+           ^^^^^^^
+warning: line 265, column 23 of dart:collection/splay_tree.dart: [DownCastComposite] (compare == null) ? Comparable.compare : compare (dynamic) will need runtime check to cast to type (K, K) → int
+      : _comparator = (compare == null) ? Comparable.compare : compare,
+                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+severe: line 266, column 65 of dart:collection/splay_tree.dart: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type K
+        _validKey = (isValidKey != null) ? isValidKey : ((v) => v is K);
+                                                                ^^^^^^
+warning: line 275, column 40 of dart:collection/splay_tree.dart: [DownCastComposite] v (dynamic) will need runtime check to cast to type V
+    other.forEach((k, v) { result[k] = v; });
+                                       ^
+warning: line 275, column 35 of dart:collection/splay_tree.dart: [DownCastComposite] k (dynamic) will need runtime check to cast to type K
+    other.forEach((k, v) { result[k] = v; });
+                                  ^
+warning: line 328, column 25 of dart:collection/splay_tree.dart: [DownCastComposite] key (Object) will need runtime check to cast to type K
+      int comp = _splay(key);
+                        ^^^
+warning: line 331, column 16 of dart:collection/splay_tree.dart: [DownCastComposite] mapRoot.value (dynamic) will need runtime check to cast to type V
+        return mapRoot.value;
+               ^^^^^^^^^^^^^
+warning: line 339, column 41 of dart:collection/splay_tree.dart: [DownCastComposite] key (Object) will need runtime check to cast to type K
+    _SplayTreeMapNode mapRoot = _remove(key);
+                                        ^^^
+warning: line 340, column 33 of dart:collection/splay_tree.dart: [DownCastComposite] mapRoot.value (dynamic) will need runtime check to cast to type V
+    if (mapRoot != null) return mapRoot.value;
+                                ^^^^^^^^^^^^^
+warning: line 363, column 14 of dart:collection/splay_tree.dart: [DownCastComposite] mapRoot.value (dynamic) will need runtime check to cast to type V
+      return mapRoot.value;
+             ^^^^^^^^^^^^^
+warning: line 394, column 38 of dart:collection/splay_tree.dart: [DownCastComposite] nodes.current (_SplayTreeNode<K>) will need runtime check to cast to type _SplayTreeMapNode<K, V>
+      _SplayTreeMapNode<K, V> node = nodes.current;
+                                     ^^^^^^^^^^^^^
+warning: line 408, column 37 of dart:collection/splay_tree.dart: [DownCastComposite] key (Object) will need runtime check to cast to type K
+    return _validKey(key) && _splay(key) == 0;
+                                    ^^^
+warning: line 420, column 41 of dart:collection/splay_tree.dart: [DownCastImplicit] node.right (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
+        if (node.right != null && visit(node.right)) return true;
+                                        ^^^^^^^^^^
+warning: line 421, column 16 of dart:collection/splay_tree.dart: [DownCastImplicit] node.left (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
+        node = node.left;
+               ^^^^^^^^^
+warning: line 425, column 18 of dart:collection/splay_tree.dart: [DownCastImplicit] _root (_SplayTreeNode<K>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
+    return visit(_root);
+                 ^^^^^
+warning: line 441, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _first.key (dynamic) will need runtime check to cast to type K
+    return _first.key;
+           ^^^^^^^^^^
+warning: line 449, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _last.key (dynamic) will need runtime check to cast to type K
+    return _last.key;
+           ^^^^^^^^^
+warning: line 545, column 22 of dart:collection/splay_tree.dart: [DownCastImplicit] _currentNode (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeMapNode<dynamic, dynamic>
+    return _getValue(_currentNode);
+                     ^^^^^^^^^^^^
+warning: line 610, column 29 of dart:collection/splay_tree.dart: [DownCastComposite] setOrMap._comparator (dynamic) will need runtime check to cast to type (K, K) → int
+        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
+                            ^^^^^^^^^^^^^^^^^^^^
+warning: line 610, column 51 of dart:collection/splay_tree.dart: [DownCastComposite] setOrMap._validKey (dynamic) will need runtime check to cast to type (Object) → bool
+        new SplayTreeSet<K>(setOrMap._comparator, setOrMap._validKey);
+                                                  ^^^^^^^^^^^^^^^^^^
+warning: line 628, column 39 of dart:collection/splay_tree.dart: [DownCastComposite] node.key (dynamic) will need runtime check to cast to type K
+  K _getValue(_SplayTreeNode node) => node.key;
+                                      ^^^^^^^^
+warning: line 633, column 42 of dart:collection/splay_tree.dart: [DownCastComposite] node.value (dynamic) will need runtime check to cast to type V
+  V _getValue(_SplayTreeMapNode node) => node.value;
+                                         ^^^^^^^^^^
+warning: line 641, column 55 of dart:collection/splay_tree.dart: [DownCastComposite] node (_SplayTreeNode<dynamic>) will need runtime check to cast to type _SplayTreeNode<K>
+  _SplayTreeNode<K> _getValue(_SplayTreeNode node) => node;
+                                                      ^^^^
+warning: line 691, column 23 of dart:collection/splay_tree.dart: [DownCastComposite] (compare == null) ? Comparable.compare : compare (dynamic) will need runtime check to cast to type (E, E) → int
+      : _comparator = (compare == null) ? Comparable.compare : compare,
+                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+severe: line 692, column 65 of dart:collection/splay_tree.dart: [InvalidRuntimeCheckError] Invalid runtime check on non-ground type E
+        _validKey = (isValidKey != null) ? isValidKey : ((v) => v is E);
+                                                                ^^^^^^
+warning: line 705, column 29 of dart:collection/splay_tree.dart: [DownCastComposite] elements (Iterable<dynamic>) will need runtime check to cast to type Iterable<E>
+    for (final E element in elements) {
+                            ^^^^^^^^
+warning: line 723, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _first.key (dynamic) will need runtime check to cast to type E
+    return _first.key;
+           ^^^^^^^^^^
+warning: line 728, column 12 of dart:collection/splay_tree.dart: [DownCastComposite] _last.key (dynamic) will need runtime check to cast to type E
+    return _last.key;
+           ^^^^^^^^^
+warning: line 739, column 40 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
+    return _validKey(object) && _splay(object) == 0;
+                                       ^^^^^^
+warning: line 751, column 20 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
+    return _remove(object) != null;
+                   ^^^^^^
+warning: line 765, column 39 of dart:collection/splay_tree.dart: [DownCastComposite] element (Object) will need runtime check to cast to type E
+      if (_validKey(element)) _remove(element);
+                                      ^^^^^^^
+warning: line 779, column 39 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
+      if (_validKey(object) && _splay(object) == 0) retainSet.add(_root.key);
+                                      ^^^^^^
+warning: line 791, column 23 of dart:collection/splay_tree.dart: [DownCastComposite] object (Object) will need runtime check to cast to type E
+    int comp = _splay(object);
+                      ^^^^^^
+severe: line 514, column 46 of dart:js: [AnalyzerError] The name 'Window' is not defined and cannot be used in an 'is' expression
+      || o is Node || o is TypedData || o is Window) {
+                                             ^^^^^^
+severe: line 553, column 46 of dart:js: [AnalyzerError] The name 'Window' is not defined and cannot be used in an 'is' expression
+      || o is Node || o is TypedData || o is Window)) {
+                                             ^^^^^^
+severe: line 467, column 5 of dart:js: [AnalyzerError] Undefined name 'getIsolateAffinityTag'
+    getIsolateAffinityTag(r'_$dart_dartClosure');
+    ^^^^^^^^^^^^^^^^^^^^^
+severe: line 552, column 60 of dart:js: [AnalyzerError] The name 'ImageData' is not defined and cannot be used in an 'is' expression
+      && (o is Blob || o is Event || o is KeyRange || o is ImageData
+                                                           ^^^^^^^^^
+severe: line 513, column 63 of dart:js: [AnalyzerError] The name 'ImageData' is not defined and cannot be used in an 'is' expression
+  } else if (o is Blob || o is Event || o is KeyRange || o is ImageData
+                                                              ^^^^^^^^^
+severe: line 465, column 5 of dart:js: [AnalyzerError] Undefined name 'getIsolateAffinityTag'
+    getIsolateAffinityTag(r'_$dart_dartObject');
+    ^^^^^^^^^^^^^^^^^^^^^
+severe: line 514, column 15 of dart:js: [AnalyzerError] The name 'Node' is not defined and cannot be used in an 'is' expression
+      || o is Node || o is TypedData || o is Window) {
+              ^^^^
+severe: line 553, column 15 of dart:js: [AnalyzerError] The name 'Node' is not defined and cannot be used in an 'is' expression
+      || o is Node || o is TypedData || o is Window)) {
+              ^^^^
+severe: line 513, column 32 of dart:js: [AnalyzerError] The name 'Event' is not defined and cannot be used in an 'is' expression
+  } else if (o is Blob || o is Event || o is KeyRange || o is ImageData
+                               ^^^^^
+severe: line 552, column 29 of dart:js: [AnalyzerError] The name 'Event' is not defined and cannot be used in an 'is' expression
+      && (o is Blob || o is Event || o is KeyRange || o is ImageData
+                            ^^^^^
+warning: line 449, column 29 of dart:js: [AnalyzerError] Local variables cannot be referenced before they are declared
+    _checkRange(start, end, length);
+                            ^^^^^^
+severe: line 465, column 5 of dart:js: [AnalyzerError] The function 'getIsolateAffinityTag' is not defined
+    getIsolateAffinityTag(r'_$dart_dartObject');
+    ^^^^^^^^^^^^^^^^^^^^^
+severe: line 552, column 43 of dart:js: [AnalyzerError] The name 'KeyRange' is not defined and cannot be used in an 'is' expression
+      && (o is Blob || o is Event || o is KeyRange || o is ImageData
+                                          ^^^^^^^^
+severe: line 513, column 46 of dart:js: [AnalyzerError] The name 'KeyRange' is not defined and cannot be used in an 'is' expression
+  } else if (o is Blob || o is Event || o is KeyRange || o is ImageData
+                                             ^^^^^^^^
+severe: line 467, column 5 of dart:js: [AnalyzerError] The function 'getIsolateAffinityTag' is not defined
+    getIsolateAffinityTag(r'_$dart_dartClosure');
+    ^^^^^^^^^^^^^^^^^^^^^
+severe: line 552, column 16 of dart:js: [AnalyzerError] The name 'Blob' is not defined and cannot be used in an 'is' expression
+      && (o is Blob || o is Event || o is KeyRange || o is ImageData
+               ^^^^
+severe: line 513, column 19 of dart:js: [AnalyzerError] The name 'Blob' is not defined and cannot be used in an 'is' expression
+  } else if (o is Blob || o is Event || o is KeyRange || o is ImageData
+                  ^^^^
+warning: line 357, column 44 of dart:js: [DownCastComposite] _convertToJS ((dynamic) → dynamic) will need runtime check to cast to type (E) → dynamic
+      : super._fromJs([]..addAll(other.map(_convertToJS)));
+                                           ^^^^^^^^^^^^
+warning: line 390, column 12 of dart:js: [DownCastComposite] super[index] (dynamic) will need runtime check to cast to type E
+    return super[index];
+           ^^^^^^^^^^^^
+warning: line 425, column 24 of dart:js: [DownCastImplicit] list (Object) will need runtime check to cast to type List<dynamic>
+    callMethod('push', list);
+                       ^^^^
+warning: line 435, column 12 of dart:js: [DownCastComposite] callMethod('splice', [index, 1])[0] (dynamic) will need runtime check to cast to type E
+    return callMethod('splice', [index, 1])[0];
+           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 440, column 12 of dart:js: [DownCastComposite] callMethod('pop') (dynamic) will need runtime check to cast to type E
+    return callMethod('pop');
+           ^^^^^^^^^^^^^^^^^
+warning: line 558, column 52 of dart:js: [DownCastImplicit] ms (num) will need runtime check to cast to type int
+    return new DateTime.fromMillisecondsSinceEpoch(ms);
+                                                   ^^
+warning: line 568, column 12 of dart:js: [DownCastImplicit] _getDartProxy(o, _DART_CLOSURE_PROPERTY_NAME, (o) => new JsFunction._fromJs(o)) (Object) will need runtime check to cast to type JsObject
+    return _getDartProxy(o, _DART_CLOSURE_PROPERTY_NAME,
+           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 571, column 12 of dart:js: [DownCastImplicit] _getDartProxy(o, _DART_OBJECT_PROPERTY_NAME, (o) => new JsArray._fromJs(o)) (Object) will need runtime check to cast to type JsObject
+    return _getDartProxy(o, _DART_OBJECT_PROPERTY_NAME,
+           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+warning: line 574, column 12 of dart:js: [DownCastImplicit] _getDartProxy(o, _DART_OBJECT_PROPERTY_NAME, (o) => new JsObject._fromJs(o)) (Object) will need runtime check to cast to type JsObject
+    return _getDartProxy(o, _DART_OBJECT_PROPERTY_NAME,
+           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^