input: Write a function to print the unique elements of a given list.
  assert print_unique([3, 4, 5, 1, 2])
  assert print_unique([3, 5, 10, 1, 2])
  assert print_unique([4, 3, 1, 2])
  assert print_unique([3, 5, 4, 1, 2])
  assert print_unique([])
output: def print_unique(lst):
      unique_elements = list(set(lst))
      for element in unique_elements:
          print(element)