def unpack(self, unpacker):
        """
        unpack this instance with data from unpacker
        """

        (a, b, c, d) = unpacker.unpack_struct(_HHHH)

        self.inner_info_ref = a
        self.outer_info_ref = b
        self.name_ref = c
        self.access_flags = d
unpack this instance with data from unpacker