docs: function(event) {
              var events = this.__collectAllPropertyValues.apply(this, ['__events', 2].concat(event || []));
  
              _.each(events, function(eventsListeners) {
                  _.each(eventsListeners, function(listener, listenerName) {
                      if (_.isUndefined(listener)) {
                          delete eventsListeners[listenerName];
                      }
                  })
              });
  
              return event ? events[event] || {} : events;
          }