Make getKeys, getValues getters (keys, values).

tests/language/method_override_test.dart

 // Copyright (c) 2011, 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.
 
 // Checks that a method with an instantiated return type can override a method
 // with a generic return type.
 
-typedef Collection<K> GetKeysFunctionType<K>();
+typedef V RemoveFunctionType<K, V>(K key);
 
 class MapBase<K, V> implements Map<K, V> {
-  Collection<K> getKeys() {
+  K remove(K key) {
     throw 'Must be implemented';
   }
 
   void Tests() {
     Expect.isTrue(this is MapBase<int, int>);
 
-    Expect.isTrue(getKeys is GetKeysFunctionType);
-    Expect.isTrue(getKeys is GetKeysFunctionType<int>);
-    Expect.isTrue(getKeys is !GetKeysFunctionType<String>);
-    Expect.isTrue(getKeys is !GetKeysFunctionType<MapBase<int, int>>);
+    Expect.isTrue(remove is RemoveFunctionType);
+    Expect.isTrue(remove is RemoveFunctionType<int, int>);
+    Expect.isTrue(remove is !RemoveFunctionType<String, int>);
+    Expect.isTrue(remove is !RemoveFunctionType<MapBase<int, int>, int>);
   }
 }
 
 
 class MethodOverrideTest extends MapBase<String, String> {
-  Collection<String> getKeys() {
-    throw 'Is implemented';
+  String remove(String key) {
+    throw 'Must be implemented';
   }
 
   void Tests() {
     Expect.isTrue(this is MethodOverrideTest);
     Expect.isTrue(this is MapBase<String, String>);
 
-    Expect.isTrue(getKeys is GetKeysFunctionType);
-    Expect.isTrue(getKeys is GetKeysFunctionType<String>);
-    Expect.isTrue(getKeys is !GetKeysFunctionType<int>);
-    Expect.isTrue(super.getKeys is GetKeysFunctionType);
-    Expect.isTrue(super.getKeys is GetKeysFunctionType<String>);
-    Expect.isTrue(super.getKeys is !GetKeysFunctionType<int>);
+    Expect.isTrue(remove is RemoveFunctionType);
+    Expect.isTrue(remove is RemoveFunctionType<String, String>);
+    Expect.isTrue(remove is !RemoveFunctionType<int, int>);
+    Expect.isTrue(super.remove is RemoveFunctionType);
+    Expect.isTrue(super.remove is RemoveFunctionType<String, String>);
+    Expect.isTrue(super.remove is !RemoveFunctionType<int, int>);
   }
 }
 
 
 main() {
   // Since method overriding is only checked statically, explicitly check
   // the subtyping relation using a function type alias.
   var x = new MethodOverrideTest();
-  Expect.isTrue(x.getKeys is GetKeysFunctionType<String>);
+  Expect.isTrue(x.remove is RemoveFunctionType<String, String>);
 
   // Perform a few more tests.
   x.Tests();
 
   var m = new MapBase<int, int>();
-  Expect.isTrue(m.getKeys is GetKeysFunctionType<int>);
+  Expect.isTrue(m.remove is RemoveFunctionType<int, int>);
 
   // Perform a few more tests.
   m.Tests();
 }