SampleFragment.kt

class SampleFragment : Fragment(R.layout.sample_fragment) {
    private val viewModel: SampleViewModel by viewModels()
    private val sampleAdapter by lazy { SampleAdapter(viewModel) }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        val rvItems = view.findViewById<RecyclerView>(R.id.rvItems)
        rvItems.layoutManager = LinearLayoutManager(context)

        view.findViewById<View>(R.id.btInsertHeaderItem).setOnClickListener {
            viewModel.onViewEvent(SampleViewEvents.InsertItemHeader)
        }

        view.findViewById<View>(R.id.btInsertFooterItem).setOnClickListener {
            viewModel.onViewEvent(SampleViewEvents.InsertItemFooter)
        }

        viewModel.pagingDataViewStates.observe(viewLifecycleOwner, Observer { pagingData ->
            sampleAdapter.submitData(viewLifecycleOwner.lifecycle, pagingData)
        })
    }
}