Filling in the data

Follow these steps to update the user interface with the data from the to-do item:

1. We start with a new test. Add the following test method to ToDoItemDetailsViewControllerTests:

   // TodoItemDetailsViewControllerTests.swift
   func test_settingToDoItem_shouldUpdateTitleLabel() {
     let title = "dummy title"
     let toDoItem = ToDoItem(title: title)
     sut.toDoItem = toDoItem
   }

At this point, we get an error from Xcode that Value of type 'ToDoItemDetailsViewController' has no member 'toDoItem'.

2. Go to ToDoItemDetailsViewController and add the toDoItem property:

   // ToDoItemDetailsViewController.swift
   class ToDoItemDetailsViewController: UIViewController {
     @IBOutlet var titleLabel: UILabel!
     @IBOutlet var dateLabel: UILabel!
     @IBOutlet var locationLabel: UILabel!
     @IBOutlet var descriptionLabel: UILabel!
     @IBOutlet var mapView: MKMapView!
   ...