| Index: pkg/compiler/lib/src/helpers/helpers.dart
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| diff --git a/pkg/compiler/lib/src/helpers/helpers.dart b/pkg/compiler/lib/src/helpers/helpers.dart
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| index 14a788708236cd8b858d9f4cfd6f81b4f1160d6a..f8f617f1178995406fa6c3e1dcc85ba3eeb021ca 100644
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| --- a/pkg/compiler/lib/src/helpers/helpers.dart
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| +++ b/pkg/compiler/lib/src/helpers/helpers.dart
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| @@ -94,7 +94,7 @@ _reportHere(DiagnosticReporter reporter, Spannable node, String debugMessage) {
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|  }
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|  
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|  /// Set of tracked objects used by [track] and [ifTracked].
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| -var _trackedObjects = new Set();
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| +var _trackedObjects = new Set<Object>();
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|  
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|  /// Global default value for the `printTrace` option of [track] and [ifTracked].
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|  bool trackWithTrace = false;
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| 
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