heapq如何解析相等的值？

import heapq

# 定义一个元素类，包含值和排序键
class Element:
    def __init__(self, value, sort_key):
        self.value = value
        self.sort_key = sort_key

    # 定义排序规则
    def __lt__(self, other):
        return self.sort_key < other.sort_key

# 创建一个空堆
heap = []

# 添加元素到堆中
heapq.heappush(heap, Element('A', 2))
heapq.heappush(heap, Element('B', 1))
heapq.heappush(heap, Element('C', 2))
heapq.heappush(heap, Element('D', 3))

# 从堆中弹出元素，按照排序键排序
while heap:
    element = heapq.heappop(heap)
    print(element.value)