final void file_truncate() {
   try {
     file.truncate(file.tell());
   } catch (IOException e) {
     throw Py.IOError(e);
   }
 }
 final long file_tell() {
   if (closed) err_closed();
   try {
     return file.tell();
   } catch (IOException e) {
     throw Py.IOError(e);
   }
 }
 public long tell() throws IOException {
   return file.tell();
 }