         let _ = try! manager.addObserver { status in
             networkStatus = status
             expectation.fulfill()
+            return false
         }
 
         waitForExpectationsWithTimeout(3, handler: nil)

    }

    func test__add_observer_new_observer_is_added() {
        let token = try! manager.addObserver { _ in }
        XCTAssertNotNil(manager.observersByID[token])
        XCTAssertTrue(network.didStartNotifier)
    }

    func test__remove_observer_observer_is_removed() {
        let token = try! manager.addObserver { _ in }
        manager.removeObserverWithToken(token)
        XCTAssertNil(manager.observersByID[token])
        XCTAssertTrue(network.didStopNotifier)

    }

    func test__add_observer_starts_notifier() {
        try! manager.addObserver { _ in false }
        XCTAssertTrue(manager.isRunning)
    }

    func test__notifier_is_only_stopped_when_last_observer_is_removed() {
        let token1 = try! manager.addObserver { _ in false }
        XCTAssertTrue(manager.isRunning)
        XCTAssertTrue(network.didStartNotifier)
        let token2 = try! manager.addObserver { _ in false }
        manager.removeObserverWithToken(token1)
        XCTAssertFalse(network.didStopNotifier)
        manager.removeObserverWithToken(token2)
