code: function CustomEventObservable() {
          var self = this;
          CustomEventObservable.superclass.constructor.apply(self, arguments);
          self.defaultFn = null;
          self.defaultTargetOnly = false;    /**
       * whether this event can bubble.
       * Defaults to: true
       * @cfg {Boolean} bubbles
       */
          /**
       * whether this event can bubble.
       * Defaults to: true
       * @cfg {Boolean} bubbles
       */
          self.bubbles = true;    /**
       * event target which binds current custom event
       * @cfg {KISSY.Event.CustomEvent.Target} currentTarget
       */
      }
docs: custom event for registering and un-registering observer for specified event on normal object.
  @class KISSY.Event.CustomEvent.CustomEventObservable
  @extends KISSY.Event.Observable
  @private
   
  custom event for registering and un-registering observer for specified event on normal object.
  @class KISSY.Event.CustomEvent.CustomEventObservable
  @extends KISSY.Event.Observable
  @private