@Override
  public void setConf(Configuration config) {
    this.conf = config;
  }
This abstract class needs to be extended to  provide implementation of actions that needs
to be performed before a particular event occurs on a metastore. These methods
are called before an event occurs on metastore.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/MetaStorePreEventListener.java