const obj = {a : 1,b: 1,c: { e : 1}}var proxy = new Proxy(obj,{get(target,property, receiver) {return Reflect.get(target, property, receiver);},set(obj, prop, value) {return obj[prop] = value;},defineProperty(target, property: string, descriptor) {return Reflect.defineProperty(target, property, descriptor);},})export function proxyTest(){proxy.a = 2;}當去掉set方法時，會執(zhí)行defineProperty；但是當有set方法時，不會執(zhí)行definePropery;這是為什么呢？