Continuation payloads

AjaxContinuationExtensions.cs

public static class AjaxContinuationExtensions
{
    public const string TOPIC = "topic";
    public const string PAYLOAD = "payload";
    
    public static AjaxContinuation SetPayload(this AjaxContinuation continuation, string topic, object payload)
    {
        continuation[PAYLOAD] = payload;
        continuation[TOPIC] = topic;

        return continuation;
    }

    public static string Topic(this AjaxContinuation continuation)
    {
        return continuation[TOPIC] as string;
    }

    public static T GetPayload<T>(this AjaxContinuation continuation) where T : class
    {
        return continuation[PAYLOAD] as T;
    }
}