@Contract(pure = true)
  private static int checkOffset(int offset, JoinLinesHandlerDelegate delegate, DocumentEx doc) {
    if (offset == CANNOT_JOIN) return offset;
    if (offset < 0) {
      LOG.error("Handler returned negative offset: handler class="+delegate.getClass()+"; offset="+offset);
      return 0;
    } else if (offset > doc.getTextLength()) {
      LOG.error("Handler returned an offset which exceeds the document length: handler class=" + delegate.getClass() +
                "; offset=" + offset + "; length=" + doc.getTextLength());
      return doc.getTextLength();
    }
    return offset;
  }
@Contract(pure = true)
  private static int checkOffset(int offset, JoinLinesHandlerDelegate delegate, DocumentEx doc)