code: func IsTouchJustReleased(id int) bool {
  	theInputState.m.RLock()
  	r := theInputState.touchDurations[id] == 0 && theInputState.prevTouchDurations[id] > 0
  	theInputState.m.RUnlock()
  	return r
  }
docs: // IsTouchJustReleased returns a boolean value indicating
  // whether the given touch is released just in the current frame.
  //
  // IsTouchJustReleased is concurrent safe.