docs: function(dialogJID, callback) {
          /**
           * Callback for QB.chat.muc.leave().
           * @param {Object} Users - list of online users
           * @callback listOnlineUsersMacCallback
           * */
  
          var self = this,
              onlineUsers = [];
  
          var iqParams = {
                  type: 'get',
                  to: dialogJID,
                  from: self.helpers.getUserCurrentJid(),
                  id: chatUtils.getUniqueId('muc_disco_items'),
              },
              builder = Utils.getEnv().browser ? $iq : XMPP.Stanza;
          var iq = chatUtils.createStanza(builder, iqParams, 'iq');
          iq.c('query', {
              xmlns: 'http://jabber.org/protocol/disco#items'
          });
  
          function _getUsers(stanza) {
              var stanzaId = stanza.attrs.id;
  
              if(self.nodeStanzasCallbacks[stanzaId]) {
                  var users = [],
                      items = stanza.getChild('query').getChildElements('item'),
                      userId;
  
                  for(var i = 0, len = items.length; i < len; i++) {
                      userId = self.helpers.getUserIdFromRoomJid(items[i].attrs.jid);
                      users.push(parseInt(userId));
                  }
  
                  callback(users);
              }
          }
  
          if (Utils.getEnv().browser) {
              self.connection.sendIQ(iq, function(stanza) {
                  var items = stanza.getElementsByTagName('item'),
                      userId;
  
                  for (var i = 0, len = items.length; i < len; i++) {
                      userId = self.helpers.getUserIdFromRoomJid(items[i].getAttribute('jid'));
                      onlineUsers.push(parseInt(userId));
                  }
  
                  callback(onlineUsers);
              });
          } else {
              self.Client.send(iq);
  
              self.nodeStanzasCallbacks[iqParams.id] = _getUsers;
          }
      }