private static int Get_imap_idx(Bry_err_wkr err_wkr, Gfh_tag img_tag) {
   byte[] val = img_tag.Atrs__get_as_bry(Imap_xtn_mgr.Bry__usemap__name);
   if (Bry_.Len_eq_0(val)) return -1;
   int rv = Bry_.To_int_or(val, Imap_xtn_mgr.Bry__usemap__prefix.length, val.length, -1);
   if (rv == -1) {
     err_wkr.Warn("invalid imap_idx", "val", val);
     return rv;
   }
   return rv;
 }
 private void Parse_cls(Gfh_tag anch_head) {
   byte[] cls_bry = anch_head.Atrs__get_as_bry(Gfh_atr_.Bry__class);
   if (Bry_.Len_eq_0(cls_bry)) return;
   this.cls_tid =
       Xoh_anch_cls_.Trie.Match_byte_or(cls_bry, 0, cls_bry.length, Xoh_anch_cls_.Tid__unknown);
 }