@Override
  public String toString() {
    return new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE).appendSuper(super.toString())
      .append("namespaceLockStatus", namespaceLockStatus.describeLockStatus()).build();
  }
@param proc must not be null
hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/TableQueue.java