@Override
    protected Procedure<Void>[] execute(Void env)
      throws ProcedureYieldException, ProcedureSuspendedException, InterruptedException {
      return new Procedure[] { new NoopProcedure<Void>(), new NoopProcedure<Void>() };
    }
Testcase for HBASE-28210, where we persist the procedure which has been inserted later to
{@link RootProcedureState} first and then crash, and then cause holes in stack ids when loading,
and finally fail the start up of master.
hbase-procedure/src/test/java/org/apache/hadoop/hbase/procedure2/TestStackIdHoles.java