How to use ts3-nodejs-library

teamspeak.on('ready', async () => {
   await teamspeak.registerEvent('textprivate');
   teamspeak.registerEvent('server');
   teamspeak.registerEvent('channel', 0);

   startTasks(teamspeak);
   resolve(teamspeak);
  });

/**
   * Updates the rank of all registered players currently online
   */
  async updateTick() {
    //get all clients online
    let onlineClients = await this.ts3.clientList({client_type: 0});

    for(let i = 0; i < onlineClients.length; i++){
      let client = onlineClients[i];

      //check if client is registered
      if(!await database.isRegisteredByTsUid(client.uniqueIdentifier)){
        return;
      }

      await exchangeChannel.postMessage(`update_tick_get_rank ${client.uniqueIdentifier}`);
    }
  }

teamspeak.on('error', (error) => {
   reject(error);
  });

let csgoRankId = cmd[2];
let rankChannelId = Teamspeak.getRankGroupFromRankId(csgoRankId);
let client = await this.ts3.getClientByUID(tsUid);
let clientGroups = client.servergroups;

async setRank(tsUid, csgoRankId){
    let tsClientList = await this.ts3.clientList({client_type: 0, client_unique_identifier: tsUid});
      let clientInfo = await tsClient.getInfo();
      let clientGroups = clientInfo.client_servergroups;
      let serverRankSgids = [];
        await tsClient.delGroups(sgidIntersection[i].toString());
      await tsClient.addGroups(newCsgoRankSgid);
      logger.debug(`Updated skill group of user ${tsClient.nickname}`);

this.ts3.on("clientconnect", ev => {
  let client = ev.client;
  logger.debug(`Client ${client.nickname} just connected`);
  client.message(config.botConfig.greetingMessage);
});
this.ts3.on("ready", () => {
  Promise.all([
    this.ts3.registerEvent("server"),
    this.ts3.registerEvent("channel", config.tsConfig.ts_welcomechannel_id),
    this.ts3.registerEvent("textprivate")
  ]).then(() => {
    logger.info("Teamspeak interface connected and ready!");
this.ts3.on('textmessage', ev => {
  Teamspeak.onMessageReceived(ev).catch(err => {
    console.log(err);
  });
});
this.ts3.on("error", e => console.log(e.message));
this.ts3.on("close", e => {
  if(e != null){
    logger.error("Connection has been lost! ", e.message);

teamspeak.on('textmessage', event => proceesCommand(event, teamspeak));

/**
   * Sends a message to the provided tsUid
   * @param tsUid
   * @param message
   * @return Promise{boolean}
   */
  async messageUser(tsUid, message){
    //We first need to get the TeamspeakClient
    let tsClientList = await this.ts3.clientList({client_type: 0, client_unique_identifier: tsUid});

    //Check if tsClientList contains at least one client
    if(tsClientList.length > 0)
    {
      let tsClient = tsClientList[0];
      tsClient.message(message)
        .then(() => {return true;})
        .catch(() => {return false;});
    }
  }