   func testRenderingBackgroundFetch() {
     
     let asyncCallbacks = expectation(description: "...")
-    var fetches: [Session.Model.BackgroundFetch] = []
     let delegate = SessionTestDelegate(start: .empty) {
-      fetches += [$0.fetch]
       var edit = $0
       if case .progressing(let handler) = $0.fetch.state {
         edit.fetch.state = .complete(.noData, handler)

            minimumInterval: .never,
            state: .idle
          ),
          Session.Model.BackgroundFetch(
            minimumInterval: .never,
            state: .progressing({ _ in})
          ),
          Session.Model.BackgroundFetch(
            minimumInterval: .never,
            state: .idle
          )

      UIApplication.shared,
      performFetchWithCompletionHandler: { _ in }
    )
    
    // 1. performFetch produces .progressing
    // 2. filter immediately produces .progressing to .complete (normally async)
    // 3. session produces .complete to .idle

    DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
      XCTAssert(
        delegate.events.map { $0.fetch }
        ==
        [
          Session.Model.BackgroundFetch( // cycle -subscribe
            minimumInterval: .never,
            state: .idle
          ),
          Session.Model.BackgroundFetch( // session -subscribe
            minimumInterval: .never,
            state: .idle
          ),
