src/vs/editor/browser/controller/mouseTarget.ts/MouseTargetFactory/_hitTestViewZone
class MouseTargetFactory:	private static _hitTestViewZone(ctx: HitTestContext, request: ResolvedHitTestRequest): IMouseTarget | null {
		const viewZoneData = ctx.getZoneAtCoord(request.mouseVerticalOffset);
		if (viewZoneData) {
			const mouseTargetType = (request.isInContentArea ? MouseTargetType.CONTENT_VIEW_ZONE : MouseTargetType.GUTTER_VIEW_ZONE);
			return request.fulfillViewZone(mouseTargetType, viewZoneData.position, viewZoneData);
		}

		return null;
	}