Horde_Kolab_Storage_Object::_getMimePartId PHP Method

    protected function _getMimePartId()
    {
        if (empty($this->_mime_part_id)) {
            throw new Horde_Kolab_Storage_Object_Exception('There is no indication which message part might contain the object data!');
        }
        return $this->_mime_part_id;
    }