Make the analyzer happy about collections.

sdk/lib/collection/list.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.collection;
 
 /**
  * Abstract implementation of a list.
  *
  * All operations are defined in terms of `length`, `operator[]`,
@@ skipping 274 matching lines @@
   }
 
   void removeAll(Iterable<Object> elements) {
     if (elements is! Set) {
       elements = elements.toSet();
     }
     _filter(this, elements.contains, false);
   }
 
 
-  void retainAll(Iterable<E> iterable) {
+  void retainAll(Iterable<E> elements) {
     if (elements is! Set) {
       elements = elements.toSet();
     }
     _filter(this, elements.contains, true);
   }
 
   void removeWhere(bool test(E element)) {
     _filter(this, test, false);
   }
 
@@ skipping 14 matching lines @@
       if (length != source.length) {
         throw new ConcurrentModificationError(source);
       }
     }
     if (retained.length != source.length) {
       source.setRange(0, retained.length, retained);
       source.length = retained.length;
     }
   }
 
+  void clear() { this.length = 0; }
+
   // List interface.
 
+  E removeLast() {
+    if (length == 0) {
+      throw new StateError("No elements");
+    }
+    E result = this[length - 1];
+    length--;
+    return result;
+  }
+
   void sort([Comparator<E> compare]) {
     Sort.sort(this, compare);
   }
 
   Map<int, E> asMap() {
     return new ListMapView(this);
   }
 
   List<E> sublist(int start, [int end]) {
     if (end == null) end = length;
@@ skipping 91 matching lines @@
    * the search at index [startIndex] to 0.
    * Returns -1 if [element] is not found.
    */
   int lastIndexOf(E element, [int startIndex]) {
     if (startIndex == null) {
       startIndex = this.length - 1;
     } else {
       if (startIndex < 0) {
         return -1;
       }
-      if (startIndex >= a.length) {
-        startIndex = a.length - 1;
+      if (startIndex >= this.length) {
+        startIndex = this.length - 1;
       }
     }
     for (int i = startIndex; i >= 0; i--) {
       if (this[i] == element) {
         return i;
       }
     }
     return -1;
   }
 
   Iterable<E> get reversed => new ReversedListIterable(this);
 }