src/vs/editor/browser/viewParts/lines/viewLine.ts/FastRenderedViewLine/getVisibleRangesForRange
class FastRenderedViewLine:	public getVisibleRangesForRange(lineNumber: number, startColumn: number, endColumn: number, context: DomReadingContext): FloatHorizontalRange[] | null {
		const startPosition = this._getCharPosition(startColumn);
		const endPosition = this._getCharPosition(endColumn);
		return [new FloatHorizontalRange(startPosition, endPosition - startPosition)];
	}