input: Write a function that takes a list of strings as input and prints the strings in alphabetical order. The function should be named `print_strings_in_order` and should accept one parameter, which is the list of strings.
  
  assert print_strings_in_order(['cat', 'dog', 'apple', 'banana'])==None
  assert print_strings_in_order(['zebra', 'ant', 'elephant', 'bear'])==None
  assert print_strings_in_order(['xylophone', 'guitar', 'piano', 'violin'])==None
  assert print_strings_in_order(['sun', 'moon', 'star', 'planet'])==None
  assert print_strings_in_order([])==None
output: def print_strings_in_order(strings):
      for s in sorted(strings):
          print(s)