def tearDown(self):
        super(SimpleInstanceTest, self).tearDown()
        CONF.network_label_regex = self.orig_conf
        CONF.ip_start = None
def git_checkout(git_url, git_branch=None, git_tag=None, git_hash=None):
    git_dst = tempfile.mkdtemp()
    g = GitManager(url=git_url, git_dst=git_dst, git_branch=git_branch, git_tag=git_tag, git_hash=git_hash)
    g.run()
    shutil.rmtree(git_dst)