def relay_microdescriptors_query_path(microdescriptor_hashes):
    """
    Generates a query path to request microdescriptors by their hashes
    from a directory server.  For example:

    >>> microdescriptor_hashes = ["Z62HG1C9PLIVs8jLi1guO48rzPdcq6tFTLi5s27Zy4U",
    ...                           "FkiLuQJe/Gqp4xsHfheh+G42TSJ77AarHOGrjazj0Q0"]
    >>> relay_microdescriptors_query_path(microdescriptor_hashes)  # doctest: +ELLIPSIS
    '/tor/micro/d/Z62HG1C9PLIVs8jL...Li5s27Zy4U-FkiLuQJe/Gqp4xsHf...rjazj0Q0'

    These query paths are defined in appendix B of [dir-spec]_.

    :param list(str) digests: The base64-encoded hashes for the descriptors.

    :returns: Query path as a :py:class:`str`.
    """
    return "/tor/micro/d/" + "-".join(microdescriptor_hashes)