Somehow I find this API counter-intuitive and painful to use.<p>- Why currentFloor() is a function not a property?<p>- Why both goingUpIndicator() and goingDownIndicator() instead of .direction property?<p>- Why name destinationDirection() instead of 
currentDirection?<p>- Why only floor_button_pressed but no in-door button press event?<p>I gave up.