How to use the omegaconf.OmegaConf.set_struct function in omegaconf

def test_deepcopy_struct(self, src: Any) -> None:
        c1 = OmegaConf.create(src)
        OmegaConf.set_struct(c1, True)
        c2 = copy.deepcopy(c1)
        assert c1 == c2
        if isinstance(c2, ListConfig):
            c2.append(1000)
        elif isinstance(c2, DictConfig):
            with raises(AttributeError):
                c2.foo = 42

def test_create_from_listconfig_preserves_metadata() -> None:
    cfg1 = ListConfig(element_type=int, is_optional=False, content=[1, 2, 3])
    OmegaConf.set_struct(cfg1, True)
    OmegaConf.set_readonly(cfg1, True)
    cfg2 = OmegaConf.create(cfg1)
    assert cfg1 == cfg2
    assert cfg1._metadata == cfg2._metadata

def test_deepcopy_and_merge_and_flags() -> None:
    c1 = OmegaConf.create(
        {"dataset": {"name": "imagenet", "path": "/datasets/imagenet"}, "defaults": []}
    )
    OmegaConf.set_struct(c1, True)
    c2 = copy.deepcopy(c1)
    with raises(ConfigKeyError):
        OmegaConf.merge(c2, OmegaConf.from_dotlist(["dataset.bad_key=yes"]))

def validate(cfg: DictConfig) -> None:
            assert not OmegaConf.is_struct(cfg)
            with pytest.raises(AttributeError):
                # noinspection PyStatementEffect
                cfg.foo

            cfg.dict1.foo = 10
            assert cfg.dict1.foo == 10

            # setting struct False on a specific typed node opens it up even though it's
            # still typed
            OmegaConf.set_struct(cfg, False)
            cfg.foo = 20
            assert cfg.foo == 20

def test_merge_config_with_struct(
    in_base: Dict[str, Any], in_merged: Dict[str, Any]
) -> None:
    base = OmegaConf.create(in_base)
    merged = OmegaConf.create(in_merged)
    OmegaConf.set_struct(base, True)
    with pytest.raises(ConfigKeyError):
        OmegaConf.merge(base, merged)

def test_struct_set_on_nested_dict() -> None:
    c = OmegaConf.create(dict(a=dict(b=10)))
    OmegaConf.set_struct(c, True)
    with pytest.raises(AttributeError):
        # noinspection PyStatementEffect
        c.foo

    assert "a" in c
    assert c.a.b == 10
    with pytest.raises(AttributeError, match=re.escape("a.foo")):
        # noinspection PyStatementEffect
        c.a.foo

def test_create_from_dictconfig_preserves_metadata() -> None:
    cfg1 = DictConfig(ref_type=Plugin, is_optional=False, content=ConcretePlugin)
    OmegaConf.set_struct(cfg1, True)
    OmegaConf.set_readonly(cfg1, True)
    cfg2 = OmegaConf.create(cfg1)
    assert cfg1 == cfg2
    assert cfg1._metadata == cfg2._metadata

defaults = hydra_cfg.defaults or []
        if config_file is not None:
            defaults.append(config_file)
        split_at = len(defaults)
        ConfigLoader._merge_default_lists(defaults, job_cfg.defaults or [])
        consumed = self._apply_defaults_overrides(overrides, defaults)

        consumed_free_job_defaults = self._apply_free_defaults(defaults, overrides)

        ConfigLoader._validate_defaults(defaults)

        # Load and defaults and merge them into cfg
        cfg = self._merge_defaults(hydra_cfg, defaults, split_at)
        OmegaConf.set_struct(cfg.hydra, True)
        OmegaConf.set_struct(cfg, strict)

        # Merge all command line overrides after enabling strict flag
        all_consumed = consumed + consumed_free_job_defaults
        remaining_overrides = [x for x in overrides if x not in all_consumed]
        cfg.merge_with_dotlist(remaining_overrides)

        remaining = consumed + consumed_free_job_defaults + remaining_overrides

        def is_hydra(x):
            return x.startswith("hydra.") or x.startswith("hydra/")

        cfg.hydra.overrides.task = [x for x in remaining if not is_hydra(x)]
        cfg.hydra.overrides.hydra = [x for x in remaining if is_hydra(x)]

        with open_dict(cfg.hydra.job):
            if "name" not in cfg.hydra.job:

job_cfg = self._create_cfg(cfg_filename=config_file, record_load=False)

        defaults = hydra_cfg.defaults or []
        if config_file is not None:
            defaults.append(config_file)
        split_at = len(defaults)
        ConfigLoader._merge_default_lists(defaults, job_cfg.defaults or [])
        consumed = self._apply_defaults_overrides(overrides, defaults)

        consumed_free_job_defaults = self._apply_free_defaults(defaults, overrides)

        ConfigLoader._validate_defaults(defaults)

        # Load and defaults and merge them into cfg
        cfg = self._merge_defaults(hydra_cfg, defaults, split_at)
        OmegaConf.set_struct(cfg.hydra, True)
        OmegaConf.set_struct(cfg, strict)

        # Merge all command line overrides after enabling strict flag
        all_consumed = consumed + consumed_free_job_defaults
        remaining_overrides = [x for x in overrides if x not in all_consumed]
        cfg.merge_with_dotlist(remaining_overrides)

        remaining = consumed + consumed_free_job_defaults + remaining_overrides

        def is_hydra(x):
            return x.startswith("hydra.") or x.startswith("hydra/")

        cfg.hydra.overrides.task = [x for x in remaining if not is_hydra(x)]
        cfg.hydra.overrides.hydra = [x for x in remaining if is_hydra(x)]

        with open_dict(cfg.hydra.job):