input: Write a function to generate a nested loop structure that prints out the elements of the given 3D list in a new line. The function should accept a 3D list as input and print each element of the list using three nested loops.
  assert nested_loop_print([[1,2,3], [4,5,6], [7,8,9]]) == None
  assert nested_loop_print([[9,8,7], [6,5,4], [3,2,1]]) == None
  assert nested_loop_print([[10,20,30], [40,50,60], [70,80,90]]) == None
output: def nested_loop_print(lst):
      for i in lst:
          for j in i:
              for k in j:
                  print(k)