docs: function(params, callback) {
          /**
           * Callback for QB.chat.message.unreadCount()
           * @param {Object} error - The error object.
           * @param {Object} res - The requested dialogs Object.
           * @callback unreadCountMessageCallback
           * */
  
          if (params && params.chat_dialog_ids && Utils.isArray(params.chat_dialog_ids)) {
              params.chat_dialog_ids = params.chat_dialog_ids.join(', ');
          }
  
          this.service.ajax({
              url: Utils.getUrl(MESSAGES_API_URL + '/unread'),
              data: params
          }, callback);
      }