protected override WorkflowCreationContext OnGetCreationContext(object[] inputs, OperationContext operationContext, Guid instanceId, WorkflowHostingResponseContext responseContext)
{
    WorkflowCreationContext creationContext = new WorkflowCreationContext();
    if (operationContext.IncomingMessageHeaders.Action.EndsWith("Create"))
    {
        Dictionary<string, object> arguments = (Dictionary<string, object>)inputs[0];
        if (arguments != null && arguments.Count > 0)
        {
            foreach (KeyValuePair<string, object> pair in arguments)
            {
                //arguments to pass to the workflow
                creationContext.WorkflowArguments.Add(pair.Key, pair.Value);
            }
        }
        //reply to client with instanceId
        responseContext.SendResponse(instanceId, null);
    }
    else if (operationContext.IncomingMessageHeaders.Action.EndsWith("CreateWithInstanceId"))
    {
        Dictionary<string, object> arguments = (Dictionary<string, object>)inputs[0];
        if (arguments != null && arguments.Count > 0)
        {
            foreach (KeyValuePair<string, object> pair in arguments)
            {
                //arguments to pass to workflow
                creationContext.WorkflowArguments.Add(pair.Key, pair.Value);
            }
        }
    }
    else
    {
        throw new InvalidOperationException("Invalid Action: " + operationContext.IncomingMessageHeaders.Action);
    }
    return creationContext;
}