function SplitLine(positionMapper, isVisible) {
            this.positionMapper = positionMapper;
            this.wrappedIndent = this.positionMapper.getWrappedLinesIndent();
            this.wrappedIndentLength = this.wrappedIndent.length;
            this.outputLineCount = this.positionMapper.getOutputLineCount();
            this._isVisible = isVisible;
        }
Gives a hint that a lot of requests are about to come in for these line numbers.