add Ember.create unit test, preventing parent object's pollute

    var K = function() {};

    Ember.create = function(obj, props) {
      K.prototype = obj;
      obj = new K();
      if (props) {
        K.prototype = obj; // prevent pollute
        for (var prop in props) {
          K.prototype[prop] = props[prop].value;
        }
        obj = new K();
      }
      K.prototype = null;

      return obj;
    };