input: def print_unique(my_list: List[Any]):
      """Prints the unique elements of a given list.
      >>> print_unique([1, 2, 3, 2, 4, 5, 4])
      1
      2
      3
      4
      5
      """
output:     seen = set()
      for item in my_list:
          if item not in seen:
              print(item)
              seen.add(item)