start method

@override void start()

Start the timer, you don't need to call it if autoStart sets true.

If call when the timer already started, then it resume the timer which this means elapsedTime and tick starts increasing from their previous value

Implementation

@override
void start() {
  if (isRunning) return;
  if (stopwatch.elapsedMicroseconds > 0) {
    resume();
  } else {
    initTimer(options.duration);
  }
  stopwatch.start();
}