private void Defaults(Role currentRole, ReadableRaftState ctx)
{
_nextRole = currentRole;
_term = ctx.Term();
_leader = ctx.Leader();
_leaderCommit = ctx.LeaderCommit();
_votedFor = ctx.VotedFor();
_renewElectionTimeout = false;
_needsFreshSnapshot = false;
_isPreElection = (currentRole == Role.FOLLOWER) && ctx.PreElection;
_steppingDownInTerm = long?.empty();
_preVotesForMe = _isPreElection ? new HashSet <MemberId>(ctx.PreVotesForMe()) : emptySet();
_votesForMe = (currentRole == Role.CANDIDATE) ? new HashSet <MemberId>(ctx.VotesForMe()) : emptySet();
_heartbeatResponses = (currentRole == Role.LEADER) ? new HashSet <MemberId>(ctx.HeartbeatResponses()) : emptySet();
_lastLogIndexBeforeWeBecameLeader = (currentRole == Role.LEADER) ? ctx.LastLogIndexBeforeWeBecameLeader() : -1;
_followerStates = (currentRole == Role.LEADER) ? ctx.FollowerStates() : new FollowerStates <MemberId>();
_commitIndex = ctx.CommitIndex();
}