Optionaloptions: CallOptionsMemberList lists all the members in the cluster.
Optionaloptions: CallOptionsMemberPromote promotes a member from raft learner (non-voting) to raft voting member.
Optionaloptions: CallOptionsMemberRemove removes an existing member from the cluster.
Optionaloptions: CallOptionsMemberUpdate updates the member configuration.
Optionaloptions: CallOptions
MemberAdd adds a member into the cluster.