/**
  * Add subscriber
  *
  * @param array  $update Update
  * @param number $keyId  Redmine key ID
  *
  * @return array
  */
 protected function _addSubscriber(array $update, $keyId = null)
 {
     $chatData = [];
     if (!$keyId) {
         return $chatData;
     }
     $chatData = [Chat::COLUMN_CHAT_ID => $this->_updateHelper->getChatId($update), Chat::COLUMN_CHAT_NAME => $this->_updateHelper->getChatName($update), Chat::COLUMN_REDMINE_KEY_ID => $keyId];
     $this->_chat->setData($chatData)->save();
     return $chatData;
 }