input: Write a function to print the values of a dictionary.
  assert print_dict_values({"a":1, "b":2, "c":3, "d":4})==None
  assert print_dict_values({"x":10, "y":20, "z":30})==None
  assert print_dict_values({"key1":100, "key2":200, "key3":300})==None
output: def print_dict_values(d):
      for value in d.values():
          print(value)