input: Write a function to swap the values of two variables x and y. After swapping, the function should print the values of both variables to verify the swap.
  
  def swap_variables(x, y):
      x, y = y, x
      print("x:", x)
      print("y:", y)
  
  assert swap_variables(5, 10)
  assert swap_variables(15, 20)
  assert swap_variables(0, 3)
  assert swap_variables(-5, 15)
  assert swap_variables(2, 2)
output: def swap_variables(x, y):
      x, y = y, x
      print("x:", x)
      print("y:", y)