private boolean parseMaybeOrPattern() {
    SyntaxTreeBuilder.Marker mark = myBuilder.mark();
    if (parseClosedPattern()) {
      if (atToken(PyTokenTypes.OR)) {
        while (atToken(PyTokenTypes.OR)) {
          nextToken();
          if (!parseClosedPattern()) {
            myBuilder.error(PyParsingBundle.message("PARSE.expected.pattern"));
            break;
          }
        }
        mark.done(PyElementTypes.OR_PATTERN);
      }
      else {
        mark.drop();
      }
      return true;
    }
    mark.drop();
    return false;
  }
private boolean parseMaybeOrPattern()