请教
let PersonType2 = (function() {

"use strict";
const PersonType2 = function(name) {
    // 确认函数被调用时使用了 new
    if (typeof new.target === "undefined") {
        // 这两处new.target分别代表啥
        throw new Error("Constructor must be called with new.");
    }
    this.name = name;
}
Object.defineProperty(PersonType2.prototype, "sayName", {
    value: function() {
        // 确认函数被调用时没有使用 new
        if (typeof new.target !== "undefined") {
            // 这两处new.target分别代表啥
            throw new Error("Method cannot be called with new.");
        }
        console.log(this.name);
    },
    enumerable: false,
    writable: true,
    configurable: true
});
return PersonType2;

}());