The function retrieves the number of votes at the end of an epoch, not at the end of a block. Furthermore, blockNumber is not an actual variable name
There is 1 instance of this issue:
https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L595
