旧版热身（历史参考）

展开查看旧版代码（仅展示，不执行）

contract={'input':'one observable object','target':'one checkable output','split':'by environment','baseline':'simple deterministic rule','metric':'task metric + failure slices','counterevidence':'condition that would change the claim'}
for k,v in contract.items(): print(f'{k}: {v}')
assert set(contract)=={'input','target','split','baseline','metric','counterevidence'}