code: public static Message buildRemove(String serverId) {
      Remove remove = Remove.newBuilder().setServerId(serverId).build();
      return Message.newBuilder().setType(MessageType.REMOVE)
                                 .setRemove(remove)
                                 .build();
    }
docs: Creates a REMOVE message.
  
  @param serverId the id of server who will be removed from the cluster
  configuration.
  @return a protobuf message.