@Override
      public void setMaxProcId(long maxProcId) {
        assert lastProcId.get() < 0 : "expected only one call to setMaxProcId()";
        lastProcId.set(maxProcId);
      }
Scheduler/Queue that contains runnable procedures.
hbase-procedure/src/main/java/org/apache/hadoop/hbase/procedure2/ProcedureExecutor.java