'date': datetime.datetime(2010, 1, 1, 20),

            'added': [

                FileNode('foobar', content='Foobar'),

                FileNode('foobar2', content='Foobar II'),

                FileNode('foo/bar/baz', content='baz here!'),

            ],

        },

    ]

    def get_backend(self):

        return vcs.get_backend(self.backend_alias)

    def get_commits(self):

        """

        Returns list of commits which builds repository for each tests.

        """

        if hasattr(self, 'commits'):

            return self.commits

    def get_new_repo_path(self):

        """

        Returns newly created repository's directory.

        """

        backend = self.get_backend()

        repo_path = get_new_dir(key)

        return repo_path

    def setUp(self):

        Backend = self.get_backend()

        self.backend_class = Backend

        self.repo_path = self.get_new_repo_path()

        self.repo = Backend(self.repo_path, create=True)

        self.imc = self.repo.in_memory_changeset

        for commit in self.get_commits():

            for node in commit.get('added', []):

                self.imc.add(FileNode(node.path, content=node.content))

            for node in commit.get('changed', []):

                self.imc.change(FileNode(node.path, content=node.content))

            for node in commit.get('removed', []):

                self.imc.remove(FileNode(node.path))

            self.imc.commit(message=unicode(commit['message']),

                            author=unicode(commit['author']),

                date=commit['date'])

        self.tip = self.repo.get_changeset()