Boilerplate.kt

interface CatApi
interface CatService
interface CatRepository
interface Scheduler
interface Context
abstract class Application {
  abstract fun onCreate()
}
abstract class AppCompatActivity


fun app(): AppComponent = TODO("")
fun common(): CommonComponent = TODO()
fun api(): ApiComponent = TODO()


interface AppComponent {
  val moshi: Moshi
  val context: Context
  val retrofit: Retrofit
  val okHttpClient: OkHttpClient
  val catApi: CatApi
  val catRepository: CatRepository
  val catService: CatService
  val mainThread: Scheduler
  val backgroundThread: Scheduler

  companion object {
    lateinit var instance: AppComponent
  }

}
interface ApiComponent: AppComponent {

  companion object {
    lateinit var instance: ApiComponent
  }
}
interface  CommonComponent : ApiComponent {

  companion object {
    lateinit var instance: CommonComponent
  }
}

// Implement the union of all properties
abstract class ComponentsImplementation(
  override val moshi: Moshi,
  override val context: Context
) : CommonComponent, AppComponent