@Override
    public @Nullable Result join(@NotNull Request req) {
      final String gap = req.document.getText(new TextRange(req.firstLineEndOffset + 1, req.secondLineStartOffset));
      final int index = gap.indexOf('\\');
      if (index >= 0) {
        if (req.leftElem == req.rightElem && SINGLE_QUOTED_STRINGS.contains(req.leftElem.getNode().getElementType())) {
          return new Result(gap.replaceFirst("\\\\\\n", ""), 0);
        }
        else {
          return new Result(gap.substring(0, index), 0);
        }
      }
      return null;
    }
@Override
    public @Nullable Result join(@NotNull Request req)