dev(narugo): update docstring

def _get_context_key(level: LevelTyping = 'global'):

    """

    Get a context key based on the specified caching level.

    :param level: The caching level to use. Can be 'global', 'process', or 'thread'.

    :type level: LevelTyping

    :return: A context key appropriate for the specified level.

    :rtype: tuple or None

    :raises ValueError: If an invalid cache level is specified.

    .. note::

        The function returns:

        - None for 'global' level

        - Process ID for 'process' level

        - (Process ID, Thread ID) tuple for 'thread' level

    """

    if level == 'global':

        return None

    elif level == 'process':

    thread-safety in multithreaded environments. It maintains the same interface

    as the built-in lru_cache, allowing you to specify options like maxsize.

    :param level: The caching level ('global', 'process', or 'thread').

    :type level: LevelTyping

    :param options: Keyword arguments to be passed to the underlying lru_cache.

    :type options: dict

    :return: A thread-safe cached version of the decorated function.

    :rtype: function

    :Example:

        >>> @ts_lru_cache(maxsize=100)

    :example:

        >>> @ts_lru_cache(level='thread', maxsize=100)

        >>> def my_function(x, y):

        ...     # Function implementation

        ...     return x + y

    .. note::

        The decorator provides three levels of caching:

        - global: Single cache shared across all processes and threads

        - process: Separate cache for each process

        - thread: Separate cache for each thread

    .. note::

        While this decorator ensures thread-safety, it may introduce some overhead

        due to lock acquisition. Use it when thread-safety is more critical than

        maximum performance in multithreaded scenarios.

    .. note::

        The decorator preserves the cache_info() and cache_clear() methods

        from the original lru_cache implementation.

    """

    _ = _get_context_key(level)

            Cached version of the original function.

            :param args: Positional arguments to be passed to the original function.

            :param __context_key: Internal context key for cache separation.

            :param kwargs: Keyword arguments to be passed to the original function.

            :return: The result of the original function call.