input: from typing import List
  
  def print_unique(my_list: List) -> None:
      """Prints the unique elements of a given list.
      >>> print_unique([1, 2, 2, 3, 4, 4])
      1
      2
      3
      4
      >>> print_unique(['a', 'b', 'b', 'c', 'd', 'd'])
      a
      b
      c
      d
      """
output:     unique_elements = sorted(set(my_list))
      for element in unique_elements:
          print(element)