code: @Override
      public void configure()
      {
          log.info("Loading Metadata from persistence.xml ...");
  
          ApplicationMetadata appMetadata = kunderaMetadata.getApplicationMetadata();
  
          try
          {
              Map<String, PersistenceUnitMetadata> metadatas = findPersistenceMetadatas();
              for (String persistenceUnit : persistenceUnits)
              {
                  if (!metadatas.containsKey(persistenceUnit))
                  {
                      log.error("Unconfigured persistence unit: " + persistenceUnit
                              + " please validate with persistence.xml");
                      throw new PersistenceUnitConfigurationException("Invalid persistence unit: " + persistenceUnit
                              + " provided");
                  }
              }
              log.info("Finishing persistence unit metadata configuration ...");
              appMetadata.addPersistenceUnitMetadata(metadatas);
          }
          catch (InvalidConfigurationException icex)
          {
              log.error("Error occurred during persistence unit configuration, Caused by: .", icex);
              throw new PersistenceLoaderException(icex);
          }
      }
docs: /*
  (non-Javadoc)
  
  @see com.impetus.kundera.configure.Configuration#configure()