anchor.diff:    external String doSumUpTo2([String? a, String? b]);
     external String doSum1Or2NonNull(String a, [String b = 'bar']);
     external String doSumUpTo2NonNull([String a = 'foo', String b = 'bar']);
  +
  +  @JS('nameInJSMethod')
  +  external String nameInDartMethod(String a, String b);
  +  @JS('nameInJSGetter')
  +  external String get nameInDartGetter;
  +  @JS('nameInJSSetter')
  +  external set nameInDartSetter(String v);
  +  external String get nameInJSSetter;
   }
   
   void createClassTest() {
  
positive.code:     globalThis.JSClass = function(foo) {
        this.foo = foo;
        this.nonNullableInt = 6;
        this.nonNullableIntReturnMethod = function() {
          return 7;
        }
  
negative.code:         return a + b;
        }
        this.doSumUpTo2NonNull = function(a, b) {
          return a + b;
        }
        this.nameInJSMethod = function(a, b) {
          return a + b;
        }
      }
  