class ExampleActivity : Activity() {
    // the controller variable is guaranteed non-null at the language level (of type `ExampleController` and not `ExampleController?`)
    // and behaves effectively as a `val` as setting it twice will throw an exception
    var controller: ExampleController by Delegates.notNullVal()
    @Inject set

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.example_layout)

        //controller.doThing()  // would compile but throw at runtime

        component().inject(this)

        controller.doThing()  // works, no need for null-safe syntax

        //controller = createAnotherController()  // would throw at runtime
    }

  // ...
}