public static Fsdb_db_mgr new_src_bin_db_mgr(Xow_wiki wiki, String version) {
   String domain_str = wiki.Domain_str();
   Fsdb_db_mgr rv = null;
   Io_url url = null;
   if (String_.Eq(version, "v1")) {
     url =
         wiki.Fsys_mgr()
             .File_dir()
             .OwnerDir()
             .GenSubDir(domain_str + "-prv"); // v1: EX: /xowa/file/en.wikipedia.org-prv/
     rv = new Fsdb_db_mgr__v1(url);
   } else if (String_.Eq(version, "v2")) {
     url = wiki.Fsys_mgr().Root_dir().GenSubDir("prv"); // v2: EX: /xowa/wiki/en.wikipedia.org/prv/
     rv = Fsdb_db_mgr_.new_detect(wiki, url, url); // note that v2 is prioritized over v1
   } else throw Err_.new_wo_type("fsdb.make:unknown fsdb_type", "version", version);
   if (rv == null)
     throw Err_.new_wo_type(
         "fsdb.make:source fsdb not found", "version", version, "url", url.Raw());
   return rv;
 }