code: func MouseButtonPressDuration(button ebiten.MouseButton) int {
  	theInputState.m.RLock()
  	s := theInputState.mouseButtonDurations[button]
  	theInputState.m.RUnlock()
  	return s
  }
docs: // MouseButtonPressDuration returns how long the mouse button is pressed in frames.
  //
  // MouseButtonPressDuration is concurrent safe.