Stochastic algorithm PR testing behaves different from local testing, for a fixed random seed.

[KexinFeng]

Description

This is shown in PR https://github.com/deepjavalibrary/djl-serving/pull/909. In the assertion in the unit test there, the output of sampling algorithm is different between testing it locally and testing it in the PR test, even though with the same fixed random seed.

Expected Behavior

This descrepency will make the stochastic algorithm changes not convenient to merge.