Jak zaimplementować RealMobject w Kotlin Android

open class DownloadModel(
    @PrimaryKey open var id: Long? = null,
    open var downloadId: Long = -1 ,
    open var title: String = "",
    open var file_path: String = "",
    open var progress: String = "",
    open var status: String = "",
    open var file_size: String = "",
    open var is_paused: Boolean = true
) : RealmObject()

android developer