def test_insert_min_heap():
heap = Heap()
items = [KeyedItem(key=i) for i in range(10)]
random_items = [item for item in items]
random.shuffle(random_items)
for item in random_items:
heap.insert(item)
for i in range(10):
assert heap.extract_root() is items[i]
assert heap.extract_root() is None
def test_delete_only_item():
heap = Heap()
item = KeyedItem(key=0)
heap.insert(item)
heap.delete(item)
assert heap.extract_root() is None