setTimeout (callback, delay, arg) {
    // If the delay is less than or equal to the RESOLUTION_MS value return a
    // native Node.js Timer instance.
    return delay <= RESOLUTION_MS
      ? setTimeout(callback, delay, arg)
      : new FastTimer(callback, delay, arg)
  }
The setTimeout() method sets a timer which executes a function once the
timer expires.
@param {Function} callback A function to be executed after the timer
expires.
@param {number} delay The time, in milliseconds that the timer should
wait before the specified function or code is executed.
@param {*} [arg] An optional argument to be passed to the callback function
when the timer expires.
@returns {NodeJS.Timeout|FastTimer}