Dagger 2 Subcomponents for Encapsulation - dagger-2

Question

How do I add a Subcomponent to a Module with an argument constructor?
Adding code here in addition to providing a github link:
ExampleApplication.java
public class ExampleApplication extends DaggerApplication {
#Inject
Database database;
#Override
public void onCreate() {
super.onCreate();
Timber.plant(new Timber.DebugTree());
Timber.i(database.name());
}
#Override
protected AndroidInjector<? extends DaggerApplication> applicationInjector() {
return DaggerApplicationComponent
.builder()
.application(this)
.build();
}
}
ApplicationComponent.java
#ApplicationScope
#Component(modules = {
ApplicationModule.class,
AndroidSupportInjectionModule.class,
ActivityBindingModule.class,
DatabaseModule.class,
})
public interface ApplicationComponent extends AndroidInjector<ExampleApplication> {
Database database();
#Component.Builder
interface Builder {
#BindsInstance
Builder application(Application application);
ApplicationComponent build();
}
#Override
void inject(ExampleApplication instance);
}
DatabaseModule.java
#Module(subcomponents = DatabaseComponent.class)
public class DatabaseModule {
#Provides
#ApplicationScope
Database provideDatabase(
#NumberOfCores int numberOfCores,
DatabaseComponent.Builder databaseComponentBuilder) {
return databaseComponentBuilder
.databaseImplModule(new DatabaseImplModule(numberOfCores / 2))
.build()
.database();
}
}
DatabaseComponent.java
#Subcomponent(modules = DatabaseImplModule.class)
public interface DatabaseComponent {
// #PrivateToDatabase <- Is this a qualifier? A scope? Neither?
Database database();
#Subcomponent.Builder
interface Builder {
Builder databaseImplModule(DatabaseImplModule databaseImplModule);
DatabaseComponent build();
}
}
DatabaseImplModule.java
#Module
public class DatabaseImplModule {
DatabaseImplModule(int concurrencyLevel) {}
#Provides DatabaseConnectionPool provideDatabaseConnectionPool() {
return new DatabaseConnectionPool();
}
#Provides DatabaseSchema provideDatabaseSchema() {
return new DatabaseSchema();
}
}
Database.java
public class Database {
#Inject
public Database() { }
public String name() {
return "I have a name";
}
}
I tried to take a look at the dagger subcomponents documentation, specifically the section Subcomponents for encapsulation. I tried to create a code example
to see if I could make it work, but with no luck. Am I missing something in the documentation? (There is a line of code commented out the #PrivateToDatabase which I am not sure what kind of annotation it is).