i have the following kotlin class which is for a recyclerview storing images. when i try to delete an image using a context menu, it crashes with an exception that r.id.recycler cannot be null. what could be the cause? class MyViewHolder(itemView: View, private val listener: MyAdapter.OnImageClickListener?) : RecyclerView.ViewHolder(itemView) {
    val imageView: ImageView = itemView.findViewById(R.id.image_view)

    init {
        imageView.setOnLongClickListener {
            val popupMenu = PopupMenu(itemView.context, itemView)
            popupMenu.inflate(R.menu.deleteimage)
            popupMenu.setOnMenuItemClickListener { menuItem ->
                return@setOnMenuItemClickListener when (menuItem.itemId) {
                    R.id.delete -> {
                        // call a listener method to delete the image at this position
                        listener?.onDeleteImage(adapterPosition, itemView.findViewById(R.id.recycler))
                        true
                    }
                    else -> false
                }
            }
            popupMenu.show()
            true
        }
    }

}