Mixin include that would respond to changes

include.js

function mixinChanged (changes) {
  changes.forEach(function (change) {
    switch (change.type) {
      case "add":
      case "update":
        this[change.name] = change.object[change.name];
        break;
      case "delete":
        delete this[name];
        break;
    }
  }, this/* .prototype */);
};

Object.defineProperty(Object.getPrototypeOf(Function), "include", {
  value: function (mixin) {
    while(mixin) {
      for (name in mixin) {
        this.prototype[name] = mixin[name];
      }
      Object.observe(mixin, mixinChanged.bind(this.prototype));
      mixin = mixin.ClassMethods;
    }
  }
});

var User = function (it) { this._name = it; };
var HasSearch = {
  ClassMethods: {
    search: function () { return [new User("Tom")]; } 
  }, 
  name: function () { return this._name; } 
};
User.include(HasSearch);

User.search()[0].name();