src/vs/editor/browser/view/renderingContext.ts/LineVisibleRanges/lastLine
class LineVisibleRanges:	public static lastLine(ranges: LineVisibleRanges[] | null): LineVisibleRanges | null {
		if (!ranges) {
			return null;
		}
		let result: LineVisibleRanges | null = null;
		for (const range of ranges) {
			if (!result || range.lineNumber > result.lineNumber) {
				result = range;
			}
		}
		return result;
	}