code: def permute_iter(elements):
      """
      iterator: returns a perumation by each call.
      """
      if len(elements) <= 1:
          yield elements
      else:
          for perm in permute_iter(elements[1:]):
              for i in range(len(elements)):
                  yield perm[:i] + elements[0:1] + perm[i:]
  
label_desc: Use image node_id 2 for calling a global function with example usage: permute_iter(elements) without return types