def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def get_git_version(self):
        VERSION_PFX = 'git version '
        version = self.run_command(
            ['version'], show_stdout=False, stdout_only=True
        )
        if version.startswith(VERSION_PFX):
            version = version[len(VERSION_PFX):].split()[0]
        else:
            version = ''
        # get first 3 positions of the git version because
        # on windows it is x.y.z.windows.t, and this parses as
        # LegacyVersion which always smaller than a Version.
        version = '.'.join(version.split('.')[:3])
        return parse_version(version)