input: Write a python function to print elements of a list.
  assert print_elements([1, 2, 3, 4, 5])==None  # Expected output: 1 2 3 4 5 
  assert print_elements([10, 20, 30])==None  # Expected output: 10 20 30 
  assert print_elements([7, 14, 21])==None  # Expected output: 7 14 21
output: def print_elements(lst):
      print(" ".join(map(str, lst)))