A: 3 - ui/common/BaseFragmentModule.java

BaseFragmentModule.java

@Module
public abstract class BaseFragmentModule {

    public static final String FRAGMENT = "BaseFragmentModule.fragment";

    static final String CHILD_FRAGMENT_MANAGER = "BaseFragmentModule.childFragmentManager";

    @Provides
    @Named(CHILD_FRAGMENT_MANAGER)
    @PerFragment
    static FragmentManager childFragmentManager(@Named(FRAGMENT) Fragment fragment) {
        return fragment.getChildFragmentManager();
    }
}