anchor.diff:        typeFormals: [T],
         returnType: typeParameterTypeNone(T),
       );
  -    expect(_inferCall(f, [], returnType: stringNone), [neverNone]);
  +    _assertTypes(_inferCall(f, [], returnType: stringNone), [neverNone]);
     }
   
     void test_unifyParametersToFunctionParam() {
  
positive.code:       typeFormals: [T],
        returnType: typeParameterTypeNone(T),
      );
      expect(_inferCall(f, []), [dynamicNone]);
    }
  
    void test_unusedReturnTypeWithUpperBound() {
  
negative.code:       ],
        returnType: typeParameterTypeNone(tTo),
      );
      _assertTypes(_inferCall(cast, [intNone]), [intNone, dynamicNone]);
    }
  
    void test_genericCastFunctionWithUpperBound() {
  