How to use the apkutils.apkfile.ZipExtFile function in apkutils

if zinfo.flag_bits & 0x40:
                # strong encryption
                raise NotImplementedError("strong encryption (flag bit 6)")

            if zinfo.flag_bits & 0x800:
                # UTF-8 filename
                fname_str = fname.decode("utf-8")
            else:
                fname_str = fname.decode("cp437")

            if fname_str != zinfo.orig_filename:
                raise BadZipFile(
                    'File name in directory %r and header %r differ.'
                    % (zinfo.orig_filename, fname))

            return ZipExtFile(zef_file, mode, zinfo, None, True)
        except Exception as ignore:
            zef_file.close()
            raise