Don't let Ember.js override setter

gistfile1.js

Person = Ember.Object.extend({
  pets: (function (key, val) {
    if (arguments.length > 1) {
      // set value
    }
    else {
      // return value
    }
  }).property('_pets')
});

Person.reopenClass({
  create: function (opts) {
    var obj, pets;

    if (opts && opts.pets) {
      pets = opts.pets;
      delete opts.pets;
    }

    obj = this._super.apply(this, arguments);
    if (pets) {
      obj.set('pets', pets);
    }
    return obj;
  }
});