public void close() {
        graphRepository.close();
        frontier.commit();
        frontier.close();
        hostsManager.close();
        schedulerLog.close();
        seedScopeFile.close();
    }
This class manages the crawler frontier

@author Luciano Barbosa
@version 1.0
ache/src/main/java/achecrawler/link/frontier/FrontierManager.java