@Override
  public String toString() {
    return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE).appendSuper(super.toString())
      .build();
  }
@deprecated only used for {@link RecoverMetaProcedure}. Should be removed along with
            {@link RecoverMetaProcedure}.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/MetaQueue.java