keys = [hashlib.sha256(json.dumps(row, sort_keys=True).encode()).hexdigest() for row in data['requests']]
naive = [hashlib.sha256(row['text'].encode()).hexdigest() for row in data['requests']]
check('包含租户版本和模型的缓存键互不相同', len(set(keys)) == 3)
check('本地反例：只按文字会产生跨租户碰撞', len(set(naive)) == 1)
result = {'unique_keys': len(set(keys)), 'naive_collision': True, 'explanation': output}
