}
		if x, ok := next(); x != 0 || ok {
			t.Fatal("iterator returned valid value after iterator Goexited")
		}
		stop()
	})
	t.Run("stop", func(t *testing.T) {
		next, stop := Pull(goexitCleanupSeq())
		x, ok := next()
		if !ok || x != 55 {
			t.Fatalf("expected (55, true) from next, got (%d, %t)", x, ok)
		}
		if !goexits(t, func() {
			stop()
		}) {
			t.Fatal("failed to Goexit from stop")