public function get($key)
    {
        if (isset($this->_values[$key])) {
            return $this->_values[$key];
        }

        return null;
    }
public function get($key)
    {
        if (isset($this->_values[$key])) {
            return $this->_values[$key];
        }

        return null;
    }
public function get ( $ key ) { if ( isset ( $ this -> _values [ $ key ] ) ) { return $ this -> _values [ $ key ] ; } return null ; }
Get a document attribute

@param string $key - name of attribute

@return mixed - value of attribute, NULL if attribute is not set
Get a document attribute