def _is_valid(self, page_index):
        """
        Check if a page index will cause entries to fall outside valid range.
        """

        try:
            self._page_cb(page_index)
        except __HOLE__:
            return False
        else:
            return True
dataset/ETHPy150Open michael-lazar/rtv/rtv/objects.py/Navigator._is_valid