public function one($name, $handler, $data=array())
	{
	    $this->ensureEvents();
	    
	    $this->_events[$name] = [];
	    
	    $this->_events[$name][] = $data ? [$handler, $data] : [$handler];
	}
public function one($name, $handler, $data=array())
	{
	    $this->ensureEvents();
	    
	    $this->_events[$name] = [];
	    
	    $this->_events[$name][] = $data ? [$handler, $data] : [$handler];
	}
public function one ( $ name , $ handler , $ data = array ( ) ) { $ this -> ensureEvents ( ) ; $ this -> _events [ $ name ] = [ ] ; $ this -> _events [ $ name ] [ ] = $ data ? [ $ handler , $ data ] : [ $ handler ] ; }
bind only one event
@param string   $name
@param callable $handler
@param array    $data
@return void
bind only one event