code: function ioStart(options) {
    options = options || {}
    log.transports.console.level = options.debug ? 'debug' : 'info'
    return ioServer(options.port, options.clientCount, options.timeoutMs)
  }
docs: The main method to start the io server.
  options = {port, clientCount, timeoutMs, debug}
   /* istanbul ignore next