private void findCommunicationAddresses() throws UnknownHostException {
        communicationAddresses = new ArrayList<InetAddress>();
        if (inetAddresses.getLoopback().isEmpty()) {
            if (inetAddresses.getRemote().isEmpty()) {
                InetAddress fallback = InetAddress.getByName(null);
                logger.debug("No loopback addresses for communication, using fallback {}", fallback);

    /**
     * Replaces local directory build cache.
     */
    void setLocal(DirectoryBuildCache local);

    /**
     * Replaces remote build cache.
     */
    void setRemote(@Nullable BuildCache remote);

    /**
     * Gets build cache service registrations
     */
    Set<BuildCacheServiceRegistration> getRegistrations();

    /**
     * Replaces build cache service registrations

		errs = AppendValidation(errs, ValidateHTTPHeaderWithAuthorityOperationName(name))
		errs = AppendValidation(errs, ValidateHTTPHeaderValue(val))
	}
	for _, name := range http.Headers.GetRequest().GetRemove() {
		errs = AppendValidation(errs, ValidateHTTPHeaderOperationName(name))
	}
	for name, val := range http.Headers.GetResponse().GetAdd() {
		errs = AppendValidation(errs, ValidateHTTPHeaderOperationName(name))

        return null;
    }

    private Collection<Ref> getRemoteRefs(GitVersionControlSpec gitSpec, boolean tags, boolean heads) {
        try {
            return configureTransport(Git.lsRemoteRepository()).setRemote(normalizeUri(gitSpec.getUrl())).setTags(tags).setHeads(heads).call();
        } catch (URISyntaxException | GitAPIException e) {
            throw wrapGitCommandException("ls-remote", gitSpec.getUrl(), null, e);
        }