input: Write a function to combine two strings and reverse the result in Python. The function should take two string arguments and return the reversed combined string.
  
  def combine_and_reverse(string1, string2):
      combined = string1 + string2
      return combined[::-1]
  
  assert combine_and_reverse("Hello ", "world!") == "!dlrow olleH"
  assert combine_and_reverse("Good", " morning!") == "!gninrom dooG"
  assert combine_and_reverse("", "test") == "tset"
  assert combine_and_reverse("Python", "") == "nohtyP"
  assert combine_and_reverse("", "") == ""
output: def combine_and_reverse(string1, string2):
      combined = string1 + string2
      return combined[::-1]