fun DatabaseReference.getCurrentUser(userId: String): Observable<FUser> {
    val dbRefsAll = mutableListOf<Observable<FUser>>()
    val refParent = child("parents").child(userId)
    dbRefsAll.add(child("parents").child(userId).dataChanges().map {
        val user = it.mapParent()
        refParent.keepSynced(true)
        user.password = it.child("password").getValue(String::class.java) ?: ""
        user
    })
    val refChild = child("children").child(userId)
    dbRefsAll.add(refChild.dataChanges().map {
        val user = it.mapChild()
        refChild.keepSynced(true)
        user.password = it.child("password").getValue(String::class.java) ?: ""
        user
    })
    return Observable.combineLatest(dbRefsAll) {
        it.forEach {
            if (it != null) with(it as FUser) {
                if (!name.isNullOrEmpty()) {
                    return@combineLatest this
                }
            }
        }
        return@combineLatest null
    }
}