input: 
  def swap_variables(x: int, y: int) -> None:
      """ Swap the values of two given variables x and y.
      >>> x, y = 5, 10
      >>> swap_variables(x, y)
      >>> print(f"x: {x}, y: {y}")
      x: 10, y: 5
      """
      x, y = y, x
  
output:     x, y = y, x