code: def test_get_by_dotted_path():
      assert get_by_dotted_path({"a": 12}, "a") == 12
      assert get_by_dotted_path({"a": 12}, "") == {"a": 12}
      assert get_by_dotted_path({"foo": {"a": 12}}, "foo.a") == 12
      assert get_by_dotted_path({"foo": {"a": 12}}, "foo.b") is None
  
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 6 for calling a global function with example usage: test_get_by_dotted_path() without return types