private function __key($key)
    {
        if ($key instanceof AnObjectHandlable) {
            $key = $key->getHandle();
        } elseif (gettype($key) == 'object') {
            $key = spl_object_hash($key);
        }

        return $key;
    }
private function __key($key)
    {
        if ($key instanceof AnObjectHandlable) {
            $key = $key->getHandle();
        } elseif (gettype($key) == 'object') {
            $key = spl_object_hash($key);
        }

        return $key;
    }
private function __key ( $ key ) { if ( $ key instanceof AnObjectHandlable ) { $ key = $ key -> getHandle ( ) ; } elseif ( gettype ( $ key ) == 'object' ) { $ key = spl_object_hash ( $ key ) ; } return $ key ; }
Return a key.

@param mixed $key

@return string
Return a key .