What is the answer_id stand for?

[WEIYanbin1999]

Dear Authors,
After I run the evaluation, I found that the output involves a answer_id slot that looks like a hash value, may I ask what it is stand for, and where and how to use them?

[ChenRunjin]

I reused some evaluation code from other repositories. The answer_id is essentially just a random hash for an answer, which is not used in our setting.