ResponderChainExample.swift

// events
public struct ComponentEvents {
   public var appEvent = Port<(component: Component, event: EventType)>()
}

subcomponent.events.appEvent.subscribe { component,  event in
    self.applicationEvent(component, event: event)
}

func applicationEvent(component: Component, event: Event) {
   switch event.type {
   case .HandledEvent(let isOn):
      state.setState = isOn
   case .HandledEvent2 :
      // handle event 2
   default:
      // send unhandled event up to parent component
      event.send(component: component, event: event.type)
   }
}