input: Write a function to print out all combinations of the given list elements in a new line using nested loops. The function should take a list of lists as input and return None, but it will print the combinations.
  
  assert nested_loop_print([[1,2,3], [4,5,6], [7,8,9]])==None
  
  The expected output after running the function will be:
  1 4 7
  1 4 8
  1 4 9
  1 5 7
  1 5 8
  1 5 9
  1 6 7
  1 6 8
  1 6 9
  2 4 7
  2 4 8
  2 4 9
  2 5 7
  2 5 8
  2 5 9
  2 6 7
  2 6 8
  2 6 9
  3 4 7
  3 4 8
  3 4 9
  3 5 7
  3 5 8
  3 5 9
  3 6 7
  3 6 8
  3 6 9
output: def nested_loop_print(lst):
      for i in lst[0]:
          for j in lst[1]:
              for k in lst[2]:
                  print(i, j, k)