def _pop_tail(self, level, node):
        sub = ((self.length - 2) >> level) & 0x01f
        if level > 5:
            child = self._pop_tail(level-5, node.array[sub])
            if child is None and sub == 0: return None
            r = self.__class__._Node(node.array[:])
            r.array[sub] = child
            return r
        elif sub == 0: return None
        else:
            r = self.__class__._Node(node.array[:])
            r.array[sub] = None
            return r
dataset/ETHPy150Open kachayev/fn.py/fn/immutable/trie.py/Vector._pop_tail/original