input: Write a function to swap the values of two variables. The function should take two variables as input and return the values of the variables after swapping.
  assert swap_variables(5, 10) == (10, 5)
  assert swap_variables(7, 3) == (3, 7)
  assert swap_variables(-1, -8) == (-8, -1)
  assert swap_variables("apple", "banana") == ("banana", "apple")
  assert swap_variables(True, False) == (False, True)
output: def swap_variables(a, b):
      return b, a