private void discardOutstandingVotesFor(final Address subject) {
    addVotesBySubject.remove(subject);
    removeVotesBySubject.remove(subject);
  }
Add a vote to the current tally. The current validator list will be updated if this vote takes
the tally past the required votes to approve the change.

@param validatorVote The vote which was cast in a block header.
consensus/common/src/main/java/org/hyperledger/besu/consensus/common/validator/blockbased/VoteTally.java