anchor.diff:  
     test_PrefixedIdentifier_parameter() {
       // SimpleIdentifier  PrefixedIdentifier  ExpressionStatement
  -    addSource('/testB.dart', '''
  +    addSource(
  +        '/testB.dart',
  +        '''
         lib B;
         class _W {M y; var _z;}
         class X extends _W {}
  
positive.code: 
    test_ConditionalExpression_partial_thenExpression() {
      // SimpleIdentifier  ConditionalExpression  ReturnStatement
      addSource('/testA.dart', '''
        int T1;
        F1() { }
        class A {int x;}''');
  
negative.code: 
    test_PrefixedIdentifier_prefix() {
      // SimpleIdentifier  PrefixedIdentifier  ExpressionStatement
      addSource(
          '/testA.dart',
          '''
        class A {static int bar = 10;}
        _B() {}''');
      addTestSource('''
  