def setup_pageflags_finish(cls) -> None:
        cls.setup_pageflags_finish_done = True
        cls._is_tail = cls.__is_tail_compound_head_bit
        cls._compound_head = cls.__compound_head_uses_low_bit

        if 'PG_tail' in cls.pageflags.keys():
            cls.PG_tail = 1 << cls.pageflags['PG_tail']
            cls._is_tail = cls.__is_tail_flag

        if cls.compound_head_name == 'first_page':
            cls._compound_head = cls.__compound_head_first_page
            if cls.PG_tail == -1:
                cls.PG_tail = 1 << cls.pageflags['PG_compound'] | 1 << cls.pageflags['PG_reclaim']
                cls._is_tail = cls.__is_tail_flagcombo