src/vs/editor/browser/widget/diffEditorWidget.ts/ViewZonesComputer/_ensureDomNodes
class ViewZonesComputer:	private static _ensureDomNodes(zones: IMyViewZone[]): IMyViewZone[] {
		return zones.map((z) => {
			if (!z.domNode) {
				z.domNode = createFakeLinesDiv();
			}
			return z;
		});
	}