private Stream<ReplicaKey> votersInState(State state) {
        return voteStates
            .values()
            .stream()
            .filter(voterState -> voterState.state().equals(state))
            .map(VoterState::replicaKey);
    }
Get the set of voters that have rejected our candidacy.

@return The set of rejecting voters
raft/src/main/java/org/apache/kafka/raft/CandidateState.java