private NavigableSet<String> getDoubleAssignedRegions(SingleProcessHBaseCluster cluster)
    throws IOException {
    NavigableSet<String> online = new TreeSet<>();
    NavigableSet<String> doubled = new TreeSet<>();
    for (RegionServerThread rst : cluster.getLiveRegionServerThreads()) {
      for (RegionInfo region : ProtobufUtil
        .getOnlineRegions(rst.getRegionServer().getRSRpcServices())) {
        if (!online.add(region.getRegionNameAsString())) {
          doubled.add(region.getRegionNameAsString());
        }
      }
    }
    return doubled;
  }
Checks if the SCP of specific dead server has been executed.
@return true if the SCP of specific serverName has been executed, false if not
hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestRollingRestart.java