def _push_tail(self, level, root, tail):
        sub = ((self.length - 1) >> level) & 0x01f
        r = self.__class__._Node(root.array[:])
        if level == 5:
            r.array[sub] = tail
        else:
            child = root.array[sub]
            if child is not None:
                r.array[sub] = self._push_tail(level-5, child, tail)
            else:
                r.array[sub] = self.__class__._make_path(5-level, tail)
        return r
dataset/ETHPy150Open kachayev/fn.py/fn/immutable/trie.py/Vector._push_tail/swapped operands of `-`