mediumBuilderDelegatio_1_4.kt

class NotificationBuilder( 
    context: Context 
) : ResourcedBuilder by context() {
    
    var contentText: CharSequence? by optional { contentTextRes }
    @StringRes var contentTextRes: Int? = null

    var title: CharSequence by required { titleRes }
    @get:StringRes var titleRes: Int? = null
    @get:DrawableRes var smallIconRes: Int by required()
    
    internal fun build(): Notification  {
        return builder
            .setContentTitle( title )
            .apply { contentText?.let { setContentText( it ) } }
            ...
            .build()
    }
}