Remove JavaIterator and MapEntry

pkg/analyzer/test/generated/all_the_rest.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.all_the_rest_test;
 
 import 'dart:collection';
@@ skipping 10426 matching lines @@
     _visitNode(superConstructorInvocation);
     _assertNoArcs();
   }
   void _assertNoArcs() {
     Set<AstNode> tails = _referenceGraph.getTails(_head);
     EngineTestCase.assertSizeOfSet(0, tails);
   }
   void _assertOneArc(AstNode tail) {
     Set<AstNode> tails = _referenceGraph.getTails(_head);
     EngineTestCase.assertSizeOfSet(1, tails);
-    JUnitTestCase.assertSame(tail, new JavaIterator(tails).next());
+    JUnitTestCase.assertSame(tail, tails.first);
   }
   ReferenceFinder _createReferenceFinder(AstNode source) =>
       new ReferenceFinder(
           source,
           _referenceGraph,
           _variableDeclarationMap,
           _constructorDeclarationMap);
   InstanceCreationExpression _makeTailConstructor(String name,
       bool isConstDeclaration, bool isConstUsage, bool inMap) {
     List<ConstructorInitializer> initializers =
@@ skipping 717 matching lines @@
     } else {
       JUnitTestCase.assertNotNullMsg("script ${scriptIndex}", scriptSource);
       String actualExternalScriptName = scriptSource.shortName;
       JUnitTestCase.assertEqualsMsg(
           "script ${scriptIndex}",
           _expectedExternalScriptName,
           actualExternalScriptName);
     }
   }
 }