@Override
  public DropDatabaseMessage buildDropDatabaseMessage(Database db) {
    return new JSONDropDatabaseMessage(HCAT_SERVER_URL, HCAT_SERVICE_PRINCIPAL, db.getName(),
        now());
  }
The JSON implementation of the MessageFactory. Constructs JSON implementations of
each message-type.
hcatalog/server-extensions/src/main/java/org/apache/hive/hcatalog/messaging/json/JSONMessageFactory.java