anchor.diff:      Source source = addSource(code);
       CompilationUnit unit = await _computeResolvedUnit(source);
       // k
  -    DartType intType = typeProvider.intType;
       FormalParameter kParameter = EngineTestCase.findNode(
           unit, code, "k, ", (node) => node is SimpleFormalParameter);
  -    expect(kParameter.identifier.propagatedType, same(intType));
  +    expect(kParameter.identifier.propagatedType, typeProvider.intType);
       // v
  -    DartType stringType = typeProvider.stringType;
       FormalParameter vParameter = EngineTestCase.findNode(
           unit, code, "v)", (node) => node is SimpleFormalParameter);
  -    expect(vParameter.identifier.propagatedType, same(stringType));
  +    expect(vParameter.identifier.propagatedType, typeProvider.stringType);
     }
   
     test_functionExpression_asInvocationArgument_functionExpressionInvocation() async {
  
positive.code:     Source source = addSource(code);
      CompilationUnit unit = await _computeResolvedUnit(source);
      // v
      DartType dynamicType = typeProvider.dynamicType;
      DartType stringType = typeProvider.stringType;
      FormalParameter vParameter = EngineTestCase.findNode(
          unit, code, "v)", (node) => node is FormalParameter);
      expect(vParameter.identifier.propagatedType, same(stringType));
      expect(vParameter.identifier.staticType, same(dynamicType));
      SimpleIdentifier vIdentifier = EngineTestCase.findNode(
          unit, code, "v;", (node) => node is SimpleIdentifier);
      expect(vIdentifier.propagatedType, same(stringType));
      expect(vIdentifier.staticType, same(dynamicType));
    }
  
    test_functionExpression_asInvocationArgument_keepIfLessSpecific() async {
  
negative.code:     // p1
      FormalParameter p1 = EngineTestCase.findNode(
          unit, code, "p1) {", (node) => node is SimpleFormalParameter);
      expect(p1.identifier.propagatedType, typeProvider.intType);
      // p2
      FormalParameter p2 = EngineTestCase.findNode(
          unit, code, "p2) {", (node) => node is SimpleFormalParameter);
      expect(p2.identifier.propagatedType, typeProvider.doubleType);
      // p3
      FormalParameter p3 = EngineTestCase.findNode(
          unit, code, "p3) {", (node) => node is SimpleFormalParameter);
      expect(p3.identifier.propagatedType, typeProvider.stringType);
    }
  
    test_initializer() async {
  