input: Write a function to swap the values of two variables. The function should take two parameters, swap them, and then print the values of both variables after the swap.
  
  assert swap_variables(5, 10)==None
  assert swap_variables(10, 20)==None
  assert swap_variables("a", "b")==None
  
  Expected Output:
  x: 10
  y: 5
  x: 20
  y: 10
  x: b
  y: a
output: def swap_variables(x, y):
      x, y = y, x
      print(f"x: {x}")
      print(f"y: {y}")