code: def _scroll(clicks, x=None, y=None):
      
      startx, starty = _position()
      width, height = _size()
  
      if x is None:
          x = startx
      else:
          if x < 0:
              x = 0
          elif x >= width:
              x = width - 1
      if y is None:
          y = starty
      else:
          if y < 0:
              y = 0
          elif y >= height:
              y = height - 1
  
      try:
          _sendMouseEvent(MOUSEEVENTF_WHEEL, x, y, dwData=clicks)
      except (PermissionError, OSError): # TODO: We need to figure out how to prevent these errors, see https://github.com/asweigart/pyautogui/issues/60
              pass
docs: Send the mouse vertical scroll event to Windows by calling the
      mouse_event() win32 function.
  
      Args:
        clicks (int): The amount of scrolling to do. A positive value is the mouse
        wheel moving forward (scrolling up), a negative value is backwards (down).
        x (int): The x position of the mouse event.
        y (int): The y position of the mouse event.
  
      Returns:
        None