code: def test_recursive_update():
      d = {"a": {"b": 1}}
      res = recursive_update(d, {"c": 2, "a": {"d": 3}})
      assert d is res
      assert res == {"a": {"b": 1, "d": 3}, "c": 2}
  
imports: import pytest
  from sacred.utils import PATHCHANGE, convert_to_nested_dict, get_by_dotted_path, is_prefix, iter_prefixes, iterate_flattened, iterate_flattened_separately, join_paths, recursive_update, set_by_dotted_path, get_inheritors, convert_camel_case_to_snake_case, apply_backspaces_and_linefeeds, module_exists, module_is_in_cache, get_package_version, parse_version, rel_path
label_desc: Use image node_id 1 for calling a global function with example usage: test_recursive_update() without return types