Using a dictionary as serialization source model for a paid cart.

PaidCartBagToJsonText.cs

var paidCartBag = new Dictionary<string, object> {
  {
    "_state", "paid"
  },
  {
    "paidItems",
    new List<object>() {
      new Dictionary<string, object> {
        { "id", "1bcd" },
        { "title", "gizmo" }
      },
      new Dictionary<string, object> {
        { "id", "3cdf" },
        { "title", "widget" },
        { "description", "A very useful item" }
      }
    }
  },
  {
    "payment",
    new Dictionary<string, object> {
      { "amount", 123.5 },
      { "currency", "USD" }
    }
  },
  {
    "timestamp", "2020-04-11T10:11:33.514+02:00"
  }
 };