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runtime/lib/function.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.
 
 class _Closure implements Function {
-
   bool operator ==(other) native "Closure_equals";
 
   int get hashCode native "Closure_hashCode";
 
   _Closure get call => this;
 
   _Closure _clone() native "Closure_clone";
 
   // No instance fields should be declared before the following 3 fields whose
   // offsets must be identical in Dart and C++.
 
   // The following 3 fields are declared both in raw_object.h (for direct access
   // from C++ code) and also here so that the offset-to-field map used by
   // deferred objects is properly initialized.
   // Caution: These fields are not Dart instances, but VM objects.
   // The fields had to be renamed here so that they would be private fields
   // in dart
   // instantiator_ ===> _instantiator
   // function_ ===> _function
   // context_ ===> _context
   var _instantiator;
   var _function;
   var _context;
 }