Sample iOS Unit Tests: Testing Segue passes data to Target ViewController

Sample iOS Unit Tests: Testing Segue passes data to Target ViewController

func testSUT_PassesDataToTargetViewController() {
        
        // declare the storyboard, source view controller, and target view controller
        let storyboard: UIStoryboard = UIStoryboard(name: "Main_iPhone", bundle: nil)
        let callingViewController = storyboard.instantiateViewControllerWithIdentifier("PlaceListViewController") as! PlaceListViewController
        let targetViewController = storyboard.instantiateViewControllerWithIdentifier("PlaceDetailsViewController") as! PlaceDetailsViewController
        
        // fetch the segue from story board
        let targetSegue: UIStoryboardSegue = UIStoryboardSegue(identifier: callingViewController.placeDetailsViewControllerSegue, source: callingViewController, destination: targetViewController)
        
        // simulate when user taps a cell - we get the associated model object and send its id (of type Int) as the sender parameter of prepareForSegue()
        let tappedModelId = 16202
        callingViewController.prepareForSegue(targetSegue, sender: tappedModelId)
        
        // confirm that prepareForSegue() properly sets the 'placeId' property of the destination view controller
        XCTAssertEqual(tappedModelId, targetViewController.placeId)
    }

This doesn't work bc your callingViewController has no member placeDetailsViewControllerSegue.
Where did you pull that method/property from??