private void StartSpans(
                IndentSet indents,
                int line,
                int textAt,
                LineSpanType lineType = LineSpanType.Normal
                )
            {
                foreach (var indent in indents.GetAll())
                {
                    var  firstLine   = line;
                    bool extendToTop = _options.VisibleEmpty &&
                                       !_options.ExtendInwardsOnly &&
                                       _lastEmptyToTextLine == 0 &&
                                       line > 0;
                    if (extendToTop)
                    {
                        firstLine = 0;
                    }

                    if (indent == textAt)
                    {
                        if (_options.VisibleAtTextEnd)
                        {
                            var span = StartSpan(firstLine, indent, lineType);
                            span.LastLine = line;
                        }
                    }
                    else if (indent < textAt)
                    {
                        var span = StartSpan(firstLine, indent, lineType);
                        span.LastLine = line;
                    }
                }
            }
            private void StartSpans(
                IndentSet indents,
                int line,
                int textAt,
                LineSpanType lineType = LineSpanType.Normal
                )
            {
                bool extendToTop = _options.VisibleEmpty &&
                                   !_options.ExtendInwardsOnly &&
                                   _lastEmptyToTextLine < 0 &&
                                   line > 0;

                foreach (var indent in indents.GetAll())
                {
                    if (indent > textAt)
                    {
                        continue;
                    }

                    if (indent == textAt && !_options.VisibleAtTextEnd)
                    {
                        continue;
                    }

                    StartSpan(extendToTop ? 0 : line, indent, lineType);
                }
            }