Horde_Kolab_Storage_Object::_appendMessage PHP Method

    protected function _appendMessage(Horde_Mime_Part $message, Horde_Mime_Headers $headers)
    {
        $result = $this->_getDriver()->appendMessage($this->_getFolder(), $message->toString(array('canonical' => true, 'stream' => true, 'headers' => $headers)));
        if (is_object($result) || $result === false || $result === null) {
            throw new Horde_Kolab_Storage_Object_Exception(sprintf('Unexpected return value (%s) when creating an object in folder "%s"!', print_r($result, true), $this->_getFolder()));
        }
        if ($result !== true) {
            $this->_backend_id = $result;
        }
        return $result;
    }