code: def test_nativestr():
      assert nativestr("teststr") == "teststr"
      assert nativestr(b"teststr") == "teststr"
      assert nativestr("null") is None
  
file_path: redis-py/tests/test_helpers.py
imports: import string
  from redis.commands.helpers import delist, list_or_args, nativestr, parse_to_dict, parse_to_list, quote_string, random_string
label_desc: Use image node_id 4 for calling a global function with example usage: test_nativestr() without return types