anchor.diff:                 yield addWidget
                        |> simpleHandler stateBuilder
                        |> buildCmd
  +            }
  +
  +    let widgetCounterAggregate =
  +        aggregate<unit,WidgetCounterEvents,WidgetId,AggregateType>
  +            AggregateType.WidgetCounter stateBuilder
  +            {
  +                let getId (evt : WidgetCreatedEvent) = evt.WidgetId
  +                yield linkEvent getId WidgetCounterEvents.Counted
               }
   
       let handlers =
  
positive.code: module AggregateIntegrationTests = 
      type AggregateType =
      | Widget
  
      type WidgetId = 
          {
  
negative.code:     type WidgetEvents =
      | Created of WidgetCreatedEvent
  
      type WidgetCounterEvents =
      | Counted of WidgetCreatedEvent
  
      let stateBuilder = StateBuilder.Empty ()
  
      let widgetHandlers = 
  