Update charted to 0.4.8 and roll

packages/collection/lib/src/utils.dart

Index: packages/collection/lib/src/utils.dart
diff --git a/packages/collection/lib/src/utils.dart b/packages/collection/lib/src/utils.dart
index c9c753777f07c1c5bd930fa4a3a7e32a5377db0f..194f99c484fc617802200d7a98b822e4184c293b 100644
--- a/packages/collection/lib/src/utils.dart
+++ b/packages/collection/lib/src/utils.dart
@@ -2,8 +2,6 @@
 // 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.
 
-library dart.pkg.collection.utils;
-
 /// A pair of values.
 class Pair<E, F> {
   E first;
@@ -11,3 +9,7 @@ class Pair<E, F> {
 
   Pair(this.first, this.last);
 }
+
+/// Returns a [Comparator] that asserts that its first argument is comparable.
+Comparator<T> defaultCompare<T>() =>
+    (value1, value2) => (value1 as Comparable).compareTo(value2);