How to use the format function in format

return new Promise((resolve, reject) => {
      // const API_HOST = "https://%s.internetofthings.ibmcloud.com/api/v0002";
      let uri = this.withProxy
        ? "/api/v0002"
        : this.withHttps
          ? format("https://%s/api/v0002", this.httpServer)
          : format("http://%s/api/v0002", this.httpServer);

      if (Array.isArray(paths)) {
        for (var i = 0, l = paths.length; i < l; i++) {
          uri += '/' + paths[i];
        }
      }

      let xhrConfig = {
        url: uri,
        method: method,
        headers: {
          'Content-Type': 'application/json'
        }
      };

      if (this.useLtpa) {

return new Promise((resolve, reject) => {
      // const API_HOST = "https://%s.internetofthings.ibmcloud.com/api/v0002";
      let uri = this.withProxy
        ? "/api/v0002"
        : format("https://%s/api/v0002", this.httpServer);

      if (Array.isArray(paths)) {
        for (var i = 0, l = paths.length; i < l; i++) {
          uri += '/' + paths[i];
        }
      }

      let xhrConfig = {
        url: uri,
        method: method,
        headers: { 
          'Content-Type': 'multipart/form-data'
        }
      };

      if (this.useLtpa) {

unmanageDevice(type, id){
    if(!this.isConnected){
      this.log.error("Client is not connected");
      //throw new Error("Client is not connected");
      //instead of throwing error, will emit 'error' event.
      this.emit('error', "Client is not connected");
    }

    var payload = new Object();

    var reqId = generateUUID();
    payload.reqId = reqId;
    payload = JSON.stringify(payload);

    let builtTopic = format(UNMANAGE_TOPIC,type,id);

    this._deviceRequests[reqId] = {action : UNMANAGE, topic : builtTopic, payload : payload};

    this.log.debug("Publishing unmanage request on topic [%s] with payload : %s", builtTopic, payload);
    this.mqtt.publish(builtTopic, payload, QOS);

    return reqId;
  }

clearLogsDevice(type, id){
    if(!this.isConnected){
      this.log.error("Client is not connected");
      //throw new Error("Client is not connected");
      //instead of throwing error, will emit 'error' event.
      this.emit('error', "Client is not connected");
    }

    var payload = new Object();

    var reqId = generateUUID();
    payload.reqId = reqId;
    payload = JSON.stringify(payload);

    let builtTopic = format(CLEAR_LOGS_TOPIC,type,id);

    this._deviceRequests[reqId] = {action : CLEAR_LOG, topic : builtTopic, payload : payload};

    this.log.debug("Publishing clear logs request on topic [%s] with payload : %s", builtTopic, payload);
    this.mqtt.publish(builtTopic, payload, QOS);

    return reqId;
  }

clearErrorCodesDevice(type, id){
    if(!this.isConnected){
      this.log.error("Client is not connected");
      //throw new Error("Client is not connected");
      //instead of throwing error, will emit 'error' event.
      this.emit('error', "Client is not connected");
    }

    var payload = new Object();

    var reqId = generateUUID();
    payload.reqId = reqId;
    payload = JSON.stringify(payload);

    let builtTopic = format(CLEAR_ERROR_CODES_TOPIC,type,id);

    this._deviceRequests[reqId] = {action: CLEAR_ERROR, topic : builtTopic, payload : payload};
 
    this.log.debug("Publishing clear error codes request on topic [%s] with payload : %s", builtTopic, payload);
    this.mqtt.publish(builtTopic, payload, QOS);

    return reqId;
  }

throw new Error("supportFirmwareActions must be a boolean");
        }

        d.supports.firmwareActions = supportFirmwareActions;
      }
    }

    var payload = new Object();
    payload.d = d;

    var reqId = generateUUID();
    payload.reqId = reqId;
    payload = JSON.stringify(payload);
    
    
    let builtTopic = format(MANAGE_TOPIC,type,id);

    this._deviceRequests[reqId] = {action : MANAGE, topic : builtTopic, payload : payload};

    this.log.debug("Publishing manage request on topic [%s] with payload : %s", builtTopic, payload);
    this.mqtt.publish(builtTopic, payload, QOS);

    return reqId;
  }

if(isDefined(data)){
      if(!isString(data)){
        throw new Error("data must be a string");
      }

      d.data = data;
    }

    var payload = new Object();
    payload.d = d;

    var reqId = generateUUID();
    payload.reqId = reqId;
    payload = JSON.stringify(payload);

    let builtTopic = format(ADD_LOG_TOPIC,type,id);

    this._deviceRequests[reqId] = {action: ADD_LOG, topic : builtTopic, payload : payload};

    this.log.debug("Publishing add log request on topic [%s] with payload : %s", builtTopic, payload);
    this.mqtt.publish(builtTopic, payload, QOS);

    return reqId;
  }