ExtendedApiContentResponse.cs

public class ExtendedApiContentResponse : ApiContentResponse, IApiContentResponse
{
    public ExtendedApiContentResponse(
        Guid id,
        string name,
        string contentType,
        DateTime createDate,
        DateTime updateDate,
        IApiContentRoute route,
        IDictionary<string, object?> properties,
        IDictionary<string, IApiContentRoute> cultures,
        IDictionary<string, object?> system)
        : base(id, name, contentType, createDate, updateDate, route, properties, cultures)
    {
        System = system;
    }

    [JsonPropertyOrder(0)]
    public IDictionary<string, object?> System { get; }
}