@Override
      public boolean matches(Object item) {
        if (!(item instanceof Procedure)) {
          return false;
        }
        Procedure<?> p = (Procedure<?>) item;
        return p.hasParent() && p.getRootProcId() == proc.getProcId();
      }
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