TypeScript:如何合并来自另一个接口的对象？

interface A {
  propA: string;
  methodA(): void;
}

interface B {
  propB: number;
  methodB(): void;
}

interface C extends A, B {
  propC: boolean;
  methodC(): void;
}

const objA: A = {
  propA: "Hello",
  methodA() {
    console.log("Method A");
  }
};

const objB: B = {
  propB: 42,
  methodB() {
    console.log("Method B");
  }
};

const objC: A & B = {
  ...objA,
  ...objB
};