@Override
    protected CloseRegionResponse execCloseRegion(ServerName server, byte[] regionName)
      throws IOException {
      CloseRegionResponse.Builder resp = CloseRegionResponse.newBuilder();
      boolean closed = ThreadLocalRandom.current().nextBoolean();
      if (closed) {
        RegionInfo hri = am.getRegionInfo(regionName);
        sendTransitionReport(server, ProtobufUtil.toRegionInfo(hri), TransitionCode.CLOSED, -1);
      }
      resp.setClosed(closed);
      return resp.build();
    }
Takes open request and then returns nothing so acts like a RS that went zombie. No response (so
proc is stuck/suspended on the Master and won't wake up.). Different with
HangThenRSCrashExecutor, HangThenRSCrashExecutor will create ServerCrashProcedure to handle the
server crash. However, this HangThenRSRestartExecutor will restart RS directly, situation for
RS crashed when SCP is not enabled.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestAssignmentManagerBase.java