How to use the mike.versions function in mike

def setUp(self):
        self.stage = stage_dir('list')
        git_init()
        all_versions = versions.Versions()
        all_versions.add('1.0')
        all_versions.add('2.0', '2.0.2')
        all_versions.add('3.0', '3.0.3', ['stable'])
        all_versions.add('4.0', aliases=['latest', 'dev'])

        with git_utils.Commit('gh-pages', 'commit message') as commit:
            commit.add_file(git_utils.FileInfo(
                'versions.json', all_versions.dumps()
            ))

def _test_deploy(self, expected_message=None,
                     expected_versions=[versions.VersionInfo('1.0')]):
        rev = git_utils.get_latest_commit('master', short=True)
        message = subprocess.check_output(['git', 'log', '-1', '--pretty=%B'],
                                          universal_newlines=True).rstrip()
        if expected_message:
            self.assertEqual(message, expected_message)
        else:
            self.assertRegex(
                message,
                r'^Deployed {} to {} with MkDocs \S+ and mike \S+$'
                .format(rev, expected_versions[0].version)
            )

        dirs = set()
        for i in expected_versions:
            dirs |= {str(i.version)} | i.aliases
        contents = {'versions.json'} | set(chain.from_iterable(

message = subprocess.check_output(['git', 'log', '-1', '--pretty=%B'],
                                          universal_newlines=True).rstrip()
        if expected_message:
            self.assertEqual(message, expected_message)
        else:
            self.assertRegex(message, r'^Copied \S+ to latest with mike \S+$')

        assertDirectory('.', {
            'versions.json',
            '1.0/index.html',
            'latest/index.html',
        }, allow_extra=True)

        with open('versions.json') as f:
            self.assertEqual(list(versions.Versions.loads(f.read())), [
                versions.VersionInfo('1.0', aliases=['latest']),
            ])

message = subprocess.check_output(['git', 'log', '-1', '--pretty=%B'],
                                          universal_newlines=True).rstrip()
        if expected_message:
            self.assertEqual(message, expected_message)
        else:
            self.assertRegex(message,
                             r'^Set title of \S+ to 1\.0\.1 with mike \S+$')

        assertDirectory('.', {
            'versions.json',
            '1.0/index.html',
        }, allow_extra=True)

        with open('versions.json') as f:
            self.assertEqual(list(versions.Versions.loads(f.read())), [
                versions.VersionInfo('1.0', '1.0.1'),
            ])

def _test_alias(self, expected_message=None):
        message = subprocess.check_output(['git', 'log', '-1', '--pretty=%B'],
                                          universal_newlines=True).rstrip()
        if expected_message:
            self.assertEqual(message, expected_message)
        else:
            self.assertRegex(message, r'^Copied \S+ to latest with mike \S+$')

        assertDirectory('.', {
            'versions.json',
            '1.0/index.html',
            'latest/index.html',
        }, allow_extra=True)

        with open('versions.json') as f:
            self.assertEqual(list(versions.Versions.loads(f.read())), [
                versions.VersionInfo('1.0', aliases=['latest']),
            ])

def _test_retitle(self, expected_message=None):
        message = subprocess.check_output(['git', 'log', '-1', '--pretty=%B'],
                                          universal_newlines=True).rstrip()
        if expected_message:
            self.assertEqual(message, expected_message)
        else:
            self.assertRegex(message,
                             r'^Set title of \S+ to 1\.0\.1 with mike \S+$')

        assertDirectory('.', {
            'versions.json',
            '1.0',
            '1.0/file.txt'
        })
        with open('versions.json') as f:
            self.assertEqual(list(versions.Versions.loads(f.read())), [
                versions.VersionInfo('1.0', '1.0.1'),
            ])

def _test_retitle(self, expected_message=None):
        message = subprocess.check_output(['git', 'log', '-1', '--pretty=%B'],
                                          universal_newlines=True).rstrip()
        if expected_message:
            self.assertEqual(message, expected_message)
        else:
            self.assertRegex(message,
                             r'^Set title of \S+ to 1\.0\.1 with mike \S+$')

        assertDirectory('.', {
            'versions.json',
            '1.0/index.html',
        }, allow_extra=True)

        with open('versions.json') as f:
            self.assertEqual(list(versions.Versions.loads(f.read())), [
                versions.VersionInfo('1.0', '1.0.1'),
            ])

self.assertRegex(
                message,
                r'^Deployed {} to {} with MkDocs \S+ and mike \S+$'
                .format(rev, expected_versions[0].version)
            )

        dirs = set()
        for i in expected_versions:
            dirs |= {str(i.version)} | i.aliases
        contents = {'versions.json'} | set(chain.from_iterable(
            (d, d + '/index.html') for d in dirs
        ))
        assertDirectory('.', contents, allow_extra=True)

        with open('versions.json') as f:
            self.assertEqual(list(versions.Versions.loads(f.read())),
                             expected_versions)

def _test_alias(self, expected_message=None, expected_src='1.0',
                    expected_aliases=['greatest']):
        if not expected_message:
            expected_message = r'^Copied {} to {} with mike \S+$'.format(
                re.escape(expected_src),
                re.escape(', '.join(expected_aliases))
            )

        self._test_state(expected_message, [
            versions.VersionInfo('1.0', aliases=expected_aliases + ['latest'])
        ])

def test_update_aliases(self):
        assertPopen(['mike', 'deploy', '1.0', 'latest'])
        assertPopen(['mike', 'deploy', '-u', '2.0', 'latest'])
        check_call_silent(['git', 'checkout', 'gh-pages'])
        self._test_deploy(expected_versions=[
            versions.VersionInfo('2.0', aliases=['latest']),
            versions.VersionInfo('1.0'),
        ])