GridConcatAdapter.kt

class BaseGridConcatAdapter(private val context: Context, private val animalAdapter: AnimalAdapter,private val spanCount:Int) :
    RecyclerView.Adapter<BaseConcatHolder<*>>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseConcatHolder<*> {
        val view = LayoutInflater.from(context).inflate(R.layout.animal_concat_row,parent,false)
        view.rv_animal_concat.layoutManager = GridLayoutManager(context, spanCount)
        return ConcatViewHolder(view)
    }

    override fun getItemCount(): Int  = 1

    override fun onBindViewHolder(holder: BaseConcatHolder<*>, position: Int) {
        when(holder){
            is ConcatViewHolder -> holder.bind(animalAdapter)
            else -> throw IllegalArgumentException("No viewholder to show this data, did you forgot to add it to the onBindViewHolder?")
        }
    }

    inner class ConcatViewHolder(itemView: View): BaseConcatHolder<AnimalAdapter>(itemView){
        override fun bind(adapter: AnimalAdapter) {
            itemView.rv_animal_concat.adapter = adapter
        }
    }
}