private String retrieveRealmFor(String scmURL){
            final String[] realms = new String[]{ null };

            SVNRepository repository;
            try {
                repository = SVNRepositoryFactory.create(SVNURL.parseURIDecoded(scmURL));
                repository.setTunnelProvider(SVNWCUtil.createDefaultOptions(true));
                repository.setAuthenticationManager(new DefaultSVNAuthenticationManager(SVNWCUtil.getDefaultConfigurationDirectory(), true, "", "", null, "") {
                    @Override
                    public SVNAuthentication getFirstAuthentication(String kind, String realm, SVNURL url) throws SVNException {
                        realms[0] = realm;
                        return super.getFirstAuthentication(kind, realm, url);
                    }
                    @Override
                    public SVNAuthentication getNextAuthentication(String kind, String realm, SVNURL url) throws SVNException {
                        realms[0] = realm;
                        return super.getNextAuthentication(kind, realm, url);
                    }

                    @Override
                    public void acknowledgeAuthentication(boolean accepted, String kind, String realm, SVNErrorMessage errorMessage, SVNAuthentication authentication) throws SVNException {
                        realms[0] = realm;
                        super.acknowledgeAuthentication(accepted, kind, realm, errorMessage, authentication);
                    }
                });
                repository.testConnection();

            } catch (SVNException e) {
                // If a problem happens, don't do anything, it implies realm doesn't exist in current cache
            }

            return realms[0];
        }