code: func SetMaxTPS(tps int) {
  	if tps < 0 && tps != UncappedTPS {
  		panic("ebiten: tps must be >= 0 or UncappedTPS")
  	}
  	atomic.StoreInt32(&currentMaxTPS, int32(tps))
  }
docs: // SetMaxTPS sets the maximum TPS (ticks per second),
  // that represents how many updating function is called per second.
  // The initial value is 60.
  //
  // If tps is UncappedTPS, TPS is uncapped and the game is updated per frame.
  // If tps is negative but not UncappedTPS, SetMaxTPS panics.
  //
  // SetMaxTPS is concurrent-safe.