code: function(params, callback) {
          /**
           * Callback for QB.chat.message.list()
           * @param {Object} error - The error object
           * @param {Object} messages - The messages object.
           * @callback listMessageCallback
           * */
  
          this.service.ajax({
              url: Utils.getUrl(MESSAGES_API_URL),
              data: params
          }, callback);
      }
docs: get a chat history. {@link https://quickblox.com/developers/Web_XMPP_Chat_Sample#List_chat_messages More info.}
  @memberof QB.chat.message
  @param {Object} params - Object of parameters.
  @param {listMessageCallback} callback - The callback function.