function originalTimingFunctionsIntact() {
        return (
          global.setTimeout === realTimingFunctions.setTimeout &&
          global.clearTimeout === realTimingFunctions.clearTimeout &&
          global.setInterval === realTimingFunctions.setInterval &&
          global.clearInterval === realTimingFunctions.clearInterval
        );
      }
Tick the Clock forward, running any enqueued timeouts along the way
@name Clock#tick
@since 1.3.0
@function
@param {int} millis The number of milliseconds to tick.