protected function parseKey($key)
    {
        if (!isset($this->keys[$key])) {
            $this->keys[$key] = explode($this->separator, $key);
        }

        return $this->keys[$key];
    }
protected function parseKey($key)
    {
        if (!isset($this->keys[$key])) {
            $this->keys[$key] = explode($this->separator, $key);
        }

        return $this->keys[$key];
    }
protected function parseKey ( $ key ) { if ( ! isset ( $ this -> keys [ $ key ] ) ) { $ this -> keys [ $ key ] = explode ( $ this -> separator , $ key ) ; } return $ this -> keys [ $ key ] ; }
Parse a separated key and cache the result
@param  string $key
@return array
Parse a separated key and cache the result