public static void CreateFakeBranchPointingAtThePullRequestTip(this IGitRepository repo, ILog log, AuthenticationInfo authentication)
        {
            var remote = repo.Network.Remotes.Single();

            log.Info("Fetching remote refs to see if there is a pull request ref");
            var remoteTips = (string.IsNullOrEmpty(authentication.Username) ?
                              repo.GetRemoteTipsForAnonymousUser(remote) :
                              repo.GetRemoteTipsUsingUsernamePasswordCredentials(remote, authentication.Username, authentication.Password))
                             .ToList();

            log.Info($"Remote Refs:{System.Environment.NewLine}" + string.Join(System.Environment.NewLine, remoteTips.Select(r => r.CanonicalName)));

            var headTipSha = repo.Head.Tip.Sha;

            var refs = remoteTips.Where(r => r.TargetIdentifier == headTipSha).ToList();

            if (refs.Count == 0)
            {
                var message = $"Couldn't find any remote tips from remote '{remote.Url}' pointing at the commit '{headTipSha}'.";
                throw new WarningException(message);
            }

            if (refs.Count > 1)
            {
                var names   = string.Join(", ", refs.Select(r => r.CanonicalName));
                var message = $"Found more than one remote tip from remote '{remote.Url}' pointing at the commit '{headTipSha}'. Unable to determine which one to use ({names}).";
                throw new WarningException(message);
            }

            var reference     = refs[0];
            var canonicalName = reference.CanonicalName;

            log.Info($"Found remote tip '{canonicalName}' pointing at the commit '{headTipSha}'.");

            if (canonicalName.StartsWith("refs/tags"))
            {
                log.Info($"Checking out tag '{canonicalName}'");
                repo.Commands.Checkout(reference.Target.Sha);
                return;
            }

            if (!canonicalName.StartsWith("refs/pull/") && !canonicalName.StartsWith("refs/pull-requests/"))
            {
                var message = $"Remote tip '{canonicalName}' from remote '{remote.Url}' doesn't look like a valid pull request.";
                throw new WarningException(message);
            }

            var fakeBranchName = canonicalName.Replace("refs/pull/", "refs/heads/pull/").Replace("refs/pull-requests/", "refs/heads/pull-requests/");

            log.Info($"Creating fake local branch '{fakeBranchName}'.");
            repo.Refs.Add(fakeBranchName, new ObjectId(headTipSha));

            log.Info($"Checking local branch '{fakeBranchName}' out.");
            repo.Commands.Checkout(fakeBranchName);
        }