code: @Override
      protected StoredClassCatalog createClassCatalog(Environment env)
              throws IllegalArgumentException, DatabaseException {
          DatabaseConfig dbConfig = new DatabaseConfig();
          dbConfig.setTemporary(false);
          dbConfig.setAllowCreate(true);
          Database catalogDb = env.openDatabase(null, CLASS_CATALOG, dbConfig);
          return new StoredClassCatalog(catalogDb);
      }
docs: Creates a persistent class catalog.
  
  @param env the environment to use.
  
  @return the class catalog.
  
  @throws OperationFailureException if one of the Read Operation Failures
  occurs, or one of the Write Operation Failures occurs.
  @throws EnvironmentFailureException - if an unexpected, internal or
  environment-wide failure occurs.
  @throws java.lang.IllegalStateException if the provided environment
  has been closed.
  @throws java.lang.IllegalStateException if there are other open handles
  for this database.