JsonResult - how to return an empty JSON result?

As of asp.net mvc 5 you could simple write:

Json(new EmptyResult(), JsonRequestBehavior.AllowGet)

In .Net Core 3.0 for a controller of type ControllerBase you can do this:

return new JsonResult(new object());

if (portfolioManagerPortalData.salesData.myYTDSalesClients == null) {
    returnJsonResult = Json(new object[] { new object() }, JsonRequestBehavior.AllowGet);
}
else {
    returnJsonResult = Json(portfolioManagerPortalData.salesData.myYTDSalesClients, JsonRequestBehavior.AllowGet);
}