ject
   *       ]
   *
   *       ...
   *
   *     });
   *
   * @class base feature: behaviors
   */

  Polymer.Base._addFeature({

    behaviors: [],

    _prepBehaviors: function() {
      if (this.behaviors.length) {
        this.behaviors = this._flattenBehaviorsList(this.behaviors);
      }
      this._prepAllBehaviors();
    },

    _flattenBehaviorsList: function(behaviors) {
      var flat = [];
      behaviors.forEach(function(b) {
        if (b instanceof Array) {
          flat = flat.concat(b)