def METHOD_NAME(path, _base=_TEST_PATH):
    if os.path.isabs(path):
        raise ValueError(
            f"ZoneInfo keys may not be absolute paths, got: {path}"
        )
    # We only care about the kinds of path normalizations that would change the
    # length of the key - e.g. a/../b -> a/b, or a/b/ -> a/b. On Windows,
    # normpath will also change from a/b to a\b, but that would still preserve
    # the length.
    new_path = os.path.normpath(path)
    if len(new_path) != len(path):
        raise ValueError(
            f"ZoneInfo keys must be normalized relative paths, got: {path}"
        )
    resolved = os.path.normpath(os.path.join(_base, new_path))
    if not resolved.startswith(_base):
        raise ValueError(
            f"ZoneInfo keys must refer to subdirectories of TZPATH, got: {path}"
        )