static public function unregister( $callBack )
	{
		if( is_null( $callBack ) )
		{
			self::$_registeredCallbacks = array();
			return true;
		}
		if( is_int( $callBack ) )
		{
			if( !isset( self::$_registered[ $callBack ] ) )
			{
				return false;
			}
			unset( self::$_registered[ $callBack ] );
			return true;
		}
		foreach( self::$_registeredCallbacks as $k => $cb )
		{
			if( $cb[ 0 ] === $callBack )
			{
				unset( self::$_registeredCallbacks[ $k ] );
				return true;
			}
		}
		return false;
	}