public List<String> getVersions(RequestScope requestScope) {
        List<String> versionList = new ArrayList<>();
        try {
            CredentialsProvider credentialsProvider = null;
            if (vcs != null) {
                log.info("vcs using {}", vcs.getVcsType());
                switch (vcs.getVcsType()) {
                    case GITHUB:
                        credentialsProvider = new UsernamePasswordCredentialsProvider(vcs.getAccessToken(), "");
                        break;
                    case BITBUCKET:
                        credentialsProvider = new UsernamePasswordCredentialsProvider("x-token-auth", vcs.getAccessToken());
                        break;
                    case GITLAB:
                        credentialsProvider = new UsernamePasswordCredentialsProvider("oauth2", vcs.getAccessToken());
                        break;
                    case AZURE_DEVOPS:
                        credentialsProvider = new UsernamePasswordCredentialsProvider("dummy", vcs.getAccessToken());
                        break;
                    default:
                        credentialsProvider = null;
                        break;
                }
            }
            Map<String, Ref> tags = Git.lsRemoteRepository()
                    .setTags(true)
                    .setRemote(source)
                    .setCredentialsProvider(credentialsProvider)
                    .callAsMap();
            tags.forEach((key, value) -> {
                versionList.add(key.replace("refs/tags/", ""));
            });
        } catch (GitAPIException e) {
            log.error(e.getMessage());
        }
        return versionList;
    }

        SshClient client = SshClient.setUpDefaultClient();
        try {
            client.start();
            GitSshdSessionFactory sshdFactory = new GitSshdSessionFactory(client);  // re-use the same client for all SSH sessions
            org.eclipse.jgit.transport.SshSessionFactory.setInstance(sshdFactory);  // replace the JSCH-based factory
            Git.lsRemoteRepository().setRemote("git@github.com:alfespa17/terraform-module-private.git").call();
        } finally {
            client.stop();
        }