@Override
      public void nodeChildrenChanged(String path) {
        if (path.equals(this.acquiredZnode)) {
          LOG.info("Received procedure start children changed event: " + path);
          waitForNewProcedures();
        } else if (path.equals(this.abortZnode)) {
          LOG.info("Received procedure abort children changed event: " + path);
          watchForAbortedProcedures();
        }
      }
Must call {@link #start(String, ProcedureMember)} before this can be used.
@param watcher  {@link ZKWatcher} to be owned by <tt>this</tt>. Closed via {@link #close()}.
@param procType name of the znode describing the procedure type
@throws KeeperException if we can't reach zookeeper
hbase-server/src/main/java/org/apache/hadoop/hbase/procedure/ZKProcedureMemberRpcs.java