docs: function (listener, prepend) {
  			if ('function' === typeof listener)
  			{
  				var self = this,
  					g = function (e)
  					{
  						e.lastListeners--;
  						self.removeListener(g);
  						listener.apply(listener, arguments);
  					};
  				g.listener = listener;
  				
  				this.addListener(g,prepend)
  			}
  			return this;
  		}