new 出来的对象如何获取所属类

class obj1 
{ 
  name:string = '' 
  age:number = 0 
} 
class obj2 
{ 
  name:string = '' 
  age:number = 0 
} 
 
let Leon = new obj2() 
if (Leon instanceof obj1) { 
  console.log('leon is obj1') 
} else if (Leon instanceof obj2) { 
  console.log('leon is obj2') 
}else {}