@BeforeClass
  public static void setUpBeforeClass() throws Exception {
    UTIL.getConfiguration().setInt(MasterProcedureConstants.MASTER_PROCEDURE_THREADS, 1);
    UTIL.startMiniCluster(StartTestingClusterOption.builder().numDataNodes(3).numRegionServers(3)
      .masterClass(HMasterForTest.class).build());
    UTIL.createMultiRegionTable(TABLE_NAME, FAMILY);
    UTIL.waitTableAvailable(TABLE_NAME);
    UTIL.getAdmin().balance(BalanceRequest.newBuilder().setIgnoreRegionsInTransition(true).build());
    UTIL.waitUntilNoRegionsInTransition();
    UTIL.getAdmin().balancerSwitch(false, true);
  }
SCP does not support rollback actually, here we just want to simulate that when there is a code
bug, SCP and its sub procedures will not hang there forever, and it will not mess up the
procedure store.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestRollbackSCP.java