def METHOD_NAME(self):
    data: MutableMapping[str, Any] = {}
    assert set_path(data, "a", value=42)
    assert data == {"a": 42}
    data = {"a": 2}
    assert set_path(data, "a", value=42)
    assert data == {"a": 42}
    data = {}
    assert set_path(data, "a", "b", value=42)
    assert data == {"a": {"b": 42}}
    data = CanonicalKeyDict({})
    assert set_path(data, "a", value=42)
    assert data == {"a": 42}