code: def onScreen(x, y=None):
      
      x, y = _unpackXY(x, y)
      x = int(x)
      y = int(y)
  
      width, height = platformModule._size()
      return 0 <= x < width and 0 <= y < height
docs: Returns whether the given xy coordinates are on the screen or not.
  
      Args:
        Either the arguments are two separate values, first arg for x and second
          for y, or there is a single argument of a sequence with two values, the
          first x and the second y.
          Example: onScreen(x, y) or onScreen([x, y])
  
      Returns:
        bool: True if the xy coordinates are on the screen at its current
          resolution, otherwise False.