VoteTally copy() {
    final Map<Address, Set<Address>> addVotesBySubject = Maps.newHashMap();
    final Map<Address, Set<Address>> removeVotesBySubject = Maps.newHashMap();

    this.addVotesBySubject.forEach(
        (key, value) -> addVotesBySubject.put(key, new TreeSet<>(value)));
    this.removeVotesBySubject.forEach(
        (key, value) -> removeVotesBySubject.put(key, new TreeSet<>(value)));

    return new VoteTally(
        new TreeSet<>(this.currentValidators), addVotesBySubject, removeVotesBySubject);
  }
The validator addresses

@return The collection of validators after the voting at the most recent block has been
    finalised.
consensus/common/src/main/java/org/hyperledger/besu/consensus/common/validator/blockbased/VoteTally.java