docs: protected AppendRequest buildAppendEmptyRequest(RaftMemberContext member) {
      final RaftLogReader reader = member.getLogReader();
  
      // Read the previous entry from the reader.
      // The reader can be null for RESERVE members.
      Indexed<RaftLogEntry> prevEntry = reader != null ? reader.getCurrentEntry() : null;
  
      DefaultRaftMember leader = raft.getLeader();
      return AppendRequest.builder()
          .withTerm(raft.getTerm())
          .withLeader(leader != null ? leader.memberId() : null)
          .withPrevLogIndex(prevEntry != null ? prevEntry.index() : reader != null ? reader.getFirstIndex() - 1 : 0)
          .withPrevLogTerm(prevEntry != null ? prevEntry.entry().term() : 0)
          .withEntries(Collections.emptyList())
          .withCommitIndex(raft.getCommitIndex())
          .build();
    }