src/vs/editor/browser/widget/diffEditorWidget.ts/SideBySideViewZonesComputer/_produceOriginalFromDiff
class SideBySideViewZonesComputer:	protected _produceOriginalFromDiff(lineChange: ILineChange, lineChangeOriginalLength: number, lineChangeModifiedLength: number): IMyViewZone | null {
		if (lineChangeModifiedLength > lineChangeOriginalLength) {
			return {
				afterLineNumber: Math.max(lineChange.originalStartLineNumber, lineChange.originalEndLineNumber),
				heightInLines: (lineChangeModifiedLength - lineChangeOriginalLength),
				domNode: null
			};
		}
		return null;
	}