code: protected final SplitBrainMergeCheckResult sendSplitBrainJoinMessageAndCheckResponse(Address target,
                                                                                           SplitBrainJoinMessage request) {
          SplitBrainJoinMessage response = sendSplitBrainJoinMessage(target, request);
          return clusterService.getClusterJoinManager().shouldMerge(response);
      }
docs: Sends a split brain join request to the target address and checks the response to see if this node should merge
  to the target address.