如何在ArkTS中合并对象？

// ts 
export class ObjectUtil { 
  static Assign<T extends {}, U>(target: T, source: U): T & U{ 
    return Object.assign(target, source); 
  } 
} 
  
//ets使用 
const target: Record<string, Object> = { "a": 1, "b": 2, }; 
const source: Record<string, Object> = { "b": 4, "c": 5, } 
const returnedTarget = ObjectUtil.Assign(target, source); 
  
console.log(JSON.stringify(target)) 
// Expected output: Object {"a":1,"b":4,"c":5}

function assign(target: Record<string, Object>, ...source: Object[]): Record<string, Object> { 
  for (let s of source) { 
    for (let k of Object.keys(s)) { 
      target[k] = Reflect.get(s, k) 
    } 
  } 
  return target 
} 
  
class D { 
  b: number 
  c: number 
  
  constructor(v1:number, v2:number) { 
    this.b = v1; 
    this.c = v2; 
  } 
} 
  
const target: Record<string, Object> = { "a": 1, "b": 2, } 
const source: D = new D(4,5) 
const returnedTarget: Record<string, Object> = assign(target, source) 
  
console.log(JSON.stringify(target)) 
// Expected output: Object {"a":1,"b":4,"c":5}