code: void shutdown() throws IOException {
          synchronized (this) {
              for (BdbEnvironmentInfo envInfo : this.envInfos) {
                  try {
                      envInfo.getClassCatalog().close();
                  } catch (DatabaseException ignore) {
                      LOGGER.log(Level.SEVERE, "Failure closing class catalog", ignore);
                  }
                  envInfo.closeAndRemoveAllDatabaseHandles();
                  
                  try (Environment env = envInfo.getEnvironment()) {
                      if (this.deleteOnExit) {
                          FileUtil.deleteDirectory(env.getHome());
                      }
                  }
              }
              this.envInfos.clear();
          }
      }
docs: Cleanly shuts down all databases in the provided environment.
  
  @throws IOException if a database delete attempt failed.
  @throws DatabaseException if an error occurs while closing the class
  catalog database.