anchor.diff:        var asyncStarParam = js_ast.TemporaryId('stream');
         var gen = emitGeneratorFn([asyncStarParam], asyncStarParam);
   
  -      var asyncStarImpl = asyncStarImplType.instantiate([returnType]);
  +      var asyncStarImpl = asyncStarImplElement.instantiate(
  +        typeArguments: [returnType],
  +        nullabilitySuffix: NullabilitySuffix.star,
  +      );
         return js.call('new #.new(#).stream', [_emitType(asyncStarImpl), gen]);
       }
   
  
positive.code:       element.returnType,
        element.typeParameters,
        parameters,
      );
    }
  
  
negative.code:     if (itemType.isDynamic) return list;
  
      // Call `new JSArray<E>.of(list)`
      var arrayType = _jsArray.instantiate(
        typeArguments: [itemType],
        nullabilitySuffix: NullabilitySuffix.star,
      );
      return js.call('#.of(#)', [_emitType(arrayType), list]);
    }
  
  