如何从DXL跳过列表中删除所有元素

class SkipListNode:
    def __init__(self, value=None, level=0):
        self.value = value
        self.forward = [None] * (level + 1)

class SkipList:
    def __init__(self, max_level=16):
        self.max_level = max_level
        self.header = SkipListNode(None, max_level)
        self.level = 0

    def delete_all(self):
        current = self.header.forward[0]
        while current:
            next_node = current.forward[0]
            del current
            current = next_node
        self.level = 0
        self.header.forward = [None] * (self.max_level + 1)

# 示例使用
skip_list = SkipList()
# 假设已经插入了一些元素
# ...
skip_list.delete_all()