| Index: pkg/compiler/lib/src/helpers/track_map.dart
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| diff --git a/pkg/compiler/lib/src/helpers/track_map.dart b/pkg/compiler/lib/src/helpers/track_map.dart
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| index 8445efe76d7fca825d0c42c28367f5e0d44c6681..8a5eb6d7bc087aa0ae1104c58e794fdc55b725cf 100644
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| --- a/pkg/compiler/lib/src/helpers/track_map.dart
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| +++ b/pkg/compiler/lib/src/helpers/track_map.dart
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| @@ -57,10 +57,10 @@ class TrackMap<K, V> implements Map<K, V> {
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|    Iterable<K> get keys => _map.keys;
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|    Iterable<V> get values => _map.values;
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|  
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| -  bool containsKey(K key) => _map.containsKey(key);
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| -  bool containsValue(V value) => _map.containsValue(value);
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| +  bool containsKey(Object key) => _map.containsKey(key);
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| +  bool containsValue(Object value) => _map.containsValue(value);
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|  
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| -  V operator [](K key) => _map[key];
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| +  V operator [](Object key) => _map[key];
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|    String toString() => _map.toString();
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|  
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|    void forEach(void action(K key, V value)) {
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| 
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