def _make_tarball(base_name, base_dir, compress="gzip", verbose=0, dry_run=0,
                  owner=None, group=None, logger=None):
    """Create a (possibly compressed) tar file from all the files under
    'base_dir'.

    'compress' must be "gzip" (the default), "bzip2", or None.

    'owner' and 'group' can be used to define an owner and a group for the
    archive that is being built. If not provided, the current owner and group
    will be used.

    The output tar file will be named 'base_name' +  ".tar", possibly plus
    the appropriate compression extension (".gz", or ".bz2").

    Returns the output filename.
    """
    tar_compression = {'gzip': 'gz', None: ''}
    compress_ext = {'gzip': '.gz'}

    if _BZ2_SUPPORTED:
        tar_compression['bzip2'] = 'bz2'
        compress_ext['bzip2'] = '.bz2'

    # flags for compression program, each element of list will be an argument
    if compress is not None and compress not in compress_ext:
        raise ValueError("bad value for 'compress', or compression format not "
                         "supported : {0}".format(compress))

    archive_name = base_name + '.tar' + compress_ext.get(compress, '')
    archive_dir = os.path.dirname(archive_name)

    if not os.path.exists(archive_dir):
        if logger is not None:
            logger.info("creating %s", archive_dir)
        if not dry_run:
            os.makedirs(archive_dir)

    # creating the tarball
    if logger is not None:
        logger.info('Creating tar archive')

    uid = _get_uid(owner)
    gid = _get_gid(group)

    def _set_uid_gid(tarinfo):
        if gid is not None:
            tarinfo.gid = gid
            tarinfo.gname = group
        if uid is not None:
            tarinfo.uid = uid
            tarinfo.uname = owner
        return tarinfo

    if not dry_run:
        tar = tarfile.open(archive_name, 'w|%s' % tar_compression[compress])
        try:
            tar.add(base_dir, filter=_set_uid_gid)
        finally:
            tar.close()

    return archive_name
Create a (possibly compressed) tar file from all the files under
    'base_dir'.

    'compress' must be "gzip" (the default), "bzip2", or None.

    'owner' and 'group' can be used to define an owner and a group for the
    archive that is being built. If not provided, the current owner and group
    will be used.

    The output tar file will be named 'base_name' +  ".tar", possibly plus
    the appropriate compression extension (".gz", or ".bz2").

    Returns the output filename.
    
product/gradle-plugin/src/main/python/pip/_vendor/distlib/_backport/shutil.py