def branch(self):

        # Note: This function will return one branch name for the changeset -

        # that might not make sense in Git where branches() is a better match

        # for the basic model

        heads = self.repository._heads(reverse=False)

        ref = heads.get(self._commit.id)

        if ref:

            return safe_unicode(ref)

    @LazyProperty

    def branches(self):

        heads = self.repository._heads(reverse=True)

    def _fix_path(self, path):

        """

        Paths are stored without trailing slash so we need to get rid off it if

        needed.

        """

        if path.endswith('/'):

            path = path.rstrip('/')

        return path

    def _get_id_for_path(self, path):

        path = safe_str(path)

    @classmethod

    def _check_url(cls, url):

        """

        Function will check given url and try to verify if it's a valid

        link. Sometimes it may happened that git will issue basic

        auth request that can cause whole API to hang when used from python

        or other external calls.

        On failures it'll raise urllib2.HTTPError, exception is also thrown

        when the return code is non 200

        """

        # check first if it's not an local url

        if os.path.isdir(url) or url.startswith('file:'):

            return True

        if url.startswith('git://'):

            return True

        if '+' in url[:url.find('://')]:

            url = url[url.find('+') + 1:]

        handlers = []

        url_obj = mercurial.util.url(url)

        if authinfo:

            # create a password manager

            passmgr = urllib2.HTTPPasswordMgrWithDefaultRealm()

            passmgr.add_password(*authinfo)

            handlers.extend((mercurial.url.httpbasicauthhandler(passmgr),

                             mercurial.url.httpdigestauthhandler(passmgr)))

        o = urllib2.build_opener(*handlers)

        o.addheaders = [('User-Agent', 'git/1.7.8.0')]  # fake some git

        try:

            resp = o.open(req)

            if resp.code != 200:

                raise Exception('Return Code is not 200')

        except Exception as e:

            # means it cannot be cloned

            raise urllib2.URLError("[%s] org_exc: %s" % (cleaned_uri, e))

        # now detect if it's proper git repo

        gitdata = resp.read()

        if 'service=git-upload-pack' not in gitdata:

        rev_filter = settings.GIT_REV_FILTER

        cmd = ['rev-list', rev_filter, '--reverse', '--date-order']

        try:

            so = self.run_git_command(cmd)

        except RepositoryError:

            # Can be raised for empty repositories

            return []

        return so.splitlines()

    def _get_all_revisions2(self):

        # alternate implementation using dulwich

        return [c.commit.id for c in self._repo.get_walker(include=includes)]

    def _get_revision(self, revision):

        """

        Given any revision identifier, returns a 40 char string with revision hash.

        """

        if self._empty:

            raise EmptyRepositoryError("There are no changesets yet")

        if revision in (None, '', 'tip', 'HEAD', 'head', -1):

            revision = -1

        return safe_unicode(self._repo.get_description() or b'unknown')

    @LazyProperty

    def contact(self):

        undefined_contact = u'Unknown'

        return undefined_contact

    @property

    def branches(self):

        if not self.revisions:

            return {}

        sortkey = lambda ctx: ctx[0]

        return OrderedDict(sorted(_branches, key=sortkey, reverse=False))

    @LazyProperty

    def closed_branches(self):

        return {}

    @LazyProperty

    def tags(self):

        return self._get_tags()

    def _get_tags(self):

        if not self.revisions:

            return {}

        sortkey = lambda ctx: ctx[0]

        return OrderedDict(sorted(_tags, key=sortkey, reverse=True))

    def tag(self, name, user, revision=None, message=None, date=None,

            **kwargs):

        """

        Creates and returns a tag for the given ``revision``.

        :param name: name for new tag

        :param user: full username, i.e.: "Joe Doe <joe.doe@example.com>"

        :param revision: changeset id for which new tag would be created

        :param message: message of the tag's commit

        :param date: date of tag's commit

                    if n not in [b'HEAD']:

                        heads[n] = val

        return heads if reverse else dict((y, x) for x, y in heads.iteritems())

    def get_changeset(self, revision=None):

        """

        Returns ``GitChangeset`` object representing commit from git repository

        at the given revision or head (most recent commit) if None given.

        """

        if isinstance(revision, GitChangeset):

            return revision

    def get_changesets(self, start=None, end=None, start_date=None,

           end_date=None, branch_name=None, reverse=False, max_revisions=None):

        """

        Returns iterator of ``GitChangeset`` objects from start to end (both

        are inclusive), in ascending date order (unless ``reverse`` is set).

        :param start: changeset ID, as str; first returned changeset

        :param end: changeset ID, as str; last returned changeset

        :param start_date: if specified, changesets with commit date less than

          ``start_date`` would be filtered out from returned set

        :param end_date: if specified, changesets with commit date greater than

        :param create=False: if set to True, would try to create repository if

           it does not exist rather than raising exception

        :param baseui=None: user data

        :param src_url=None: would try to clone repository from given location

        :param update_after_clone=False: sets update of working copy after

          making a clone

        """

        if not isinstance(repo_path, str):

            raise VCSError('Mercurial backend requires repository path to '

                           'be instance of <str> got %s instead' %

                           type(repo_path))

        self.path = abspath(repo_path)

        self.baseui = baseui or mercurial.ui.ui()

        # We've set path and ui, now we can set _repo itself

        self._repo = self._get_repo(create, src_url, update_after_clone)

    @property

    def _empty(self):

        """

        Checks if repository is empty ie. without any changesets

        """

        # TODO: Following raises errors when using InMemoryChangeset...

        # return len(self._repo.changelog) == 0

        if authinfo:

            # create a password manager

            passmgr = urllib2.HTTPPasswordMgrWithDefaultRealm()

            passmgr.add_password(*authinfo)

            handlers.extend((mercurial.url.httpbasicauthhandler(passmgr),

                             mercurial.url.httpdigestauthhandler(passmgr)))

        o = urllib2.build_opener(*handlers)

        o.addheaders = [('Content-Type', 'application/mercurial-0.1'),

                        ('Accept', 'application/mercurial-0.1')]

        try:

            resp = o.open(req)

            if resp.code != 200:

                raise Exception('Return Code is not 200')

        except Exception as e:

            # means it cannot be cloned

            raise urllib2.URLError("[%s] org_exc: %s" % (cleaned_uri, e))

        if not url_prefix: # skip svn+http://... (and git+... too)

            # now check if it's a proper hg repo

            try:

        return True

    def _get_repo(self, create, src_url=None, update_after_clone=False):

        """

        Function will check for mercurial repository in given path and return

        a localrepo object. If there is no repository in that path it will

        raise an exception unless ``create`` parameter is set to True - in

        that case repository would be created and returned.

        If ``src_url`` is given, would try to clone repository from the

        location at given clone_point. Additionally it'll make update to

        working copy accordingly to ``update_after_clone`` flag

        """

        try:

            if src_url:

                url = safe_bytes(self._get_url(src_url))

                opts = {}

                if not update_after_clone:

                    opts.update({'noupdate': True})

                MercurialRepository._check_url(url, self.baseui)

                mercurial.commands.clone(self.baseui, url, self.path, **opts)

                # Don't try to create if we've already cloned repo

                create = False

            return mercurial.localrepo.instance(self.baseui, self.path, create=create)

    def get_hook_location(self):

        """

        returns absolute path to location where hooks are stored

        """

        return os.path.join(self.path, '.hg', '.hgrc')

    def get_changeset(self, revision=None):

        """

        Returns ``MercurialChangeset`` object representing repository's

        changeset at the given ``revision``.

        """

    def get_changesets(self, start=None, end=None, start_date=None,

                       end_date=None, branch_name=None, reverse=False, max_revisions=None):

        """

        Returns iterator of ``MercurialChangeset`` objects from start to end

        (both are inclusive)

        :param start: None, str, int or mercurial lookup format

        :param end:  None, str, int or mercurial lookup format

        :param start_date:

        :param end_date:

        :param branch_name: