怎么实现类似oc的代理模式

declare interface Animal { 
  eat(): void; 
  run(): void; 
} 
 
export class Kitten implements Animal { 
  public eat(): void { 
    console.log("The kitten is eating fish"); 
  } 
  public run(): void { 
    console.log("The kitten is running"); 
  } 
} 
 
export class Dog implements Animal { 
  public eat(): void { 
    console.log("The dog is eating fish"); 
  } 
  public run(): void { 
    console.log("The dog is running"); 
  } 
}