anchor.diff:      if (itemType == const DynamicType()) return list;
   
       // Call `new JSArray<E>.of(list)`
  -    var arrayType =
  -        InterfaceType(_jsArrayClass, Nullability.legacy, [itemType]);
  -    return js.call('#.of(#)', [_emitType(arrayType), list]);
  +    var arrayType = _emitInterfaceType(
  +        InterfaceType(_jsArrayClass, Nullability.legacy, [itemType]),
  +        emitNullability: false);
  +    return js.call('#.of(#)', [arrayType, list]);
     }
   
     js_ast.Expression _emitConstList(
  
positive.code: 
    js_ast.Expression _emitMapImplType(InterfaceType type, {bool identity}) {
      var typeArgs = type.typeArguments;
      if (typeArgs.isEmpty) return _emitType(type);
      identity ??= _typeRep.isPrimitive(typeArgs[0]);
      var c = identity ? _identityHashMapImplClass : _linkedHashMapImplClass;
      return _emitType(InterfaceType(c, Nullability.legacy, typeArgs));
    }
  
    js_ast.Expression _emitSetImplType(InterfaceType type, {bool identity}) {
      var typeArgs = type.typeArguments;
      if (typeArgs.isEmpty) return _emitType(type);
      identity ??= _typeRep.isPrimitive(typeArgs[0]);
      var c = identity ? _identityHashSetImplClass : _linkedHashSetImplClass;
      return _emitType(InterfaceType(c, Nullability.legacy, typeArgs));
    }
  
    js_ast.Expression _emitObjectLiteral(Arguments node) {
  
negative.code:       var gen = emitGeneratorFn((_) => [_asyncStarController]);
  
        var returnType = _expectedReturnType(function, _coreTypes.streamClass);
        var asyncStarImpl = _emitInterfaceType(
            InterfaceType(_asyncStarImplClass, Nullability.legacy, [returnType]),
            emitNullability: false);
        return js.call('new #.new(#).stream', [asyncStarImpl, gen]);
      }
  
      assert(function.asyncMarker == AsyncMarker.Async);
  