anchor.diff:            "Unexpected instantiation of $type with $instantiation: $result");
       }
   
  -    testRelations(DartType a, DartType b, bool areEqual, bool isSubtype) {
  +    testRelations(DartType a, DartType b,
  +        {bool areEqual: false, bool isSubtype: false}) {
  +      if (areEqual) {
  +        isSubtype = true;
  +      }
         Expect.equals(
             areEqual,
             a == b,
  
positive.code:     FunctionType F4 = env.getFieldType('F4');
      FunctionType F5 = env.getFieldType('F5');
      FunctionType F6 = env.getFieldType('F6');
  
      testToString(F1, 'void Function<#A>(#A)');
      testToString(F2, 'void Function<#A>(#A)');
  
negative.code:     testBounds(F4, [Object_, Object_]);
      testBounds(F5, [num_]);
      testBounds(F6, [int_]);
      testBounds(F7, [num_]);
      testBounds(F8, [num_]);
  
      testInstantiate(F1, [C1], 'void Function(C1)');
      testInstantiate(F2, [C2], 'void Function(C2)');
  