LocationActivity.kt

class LocationActivity : AppCompatActivity() {

    private lateinit var locationViewModel: LocationViewModel
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_location)

        locationViewModel = ViewModelProviders.of(this).get(LocationViewModel::class.java)
    }
    
    private fun startLocationUpdate() {
        locationViewModel.getLocationData().observe(this, Observer {
            latLong.text =  getString(R.string.latLong, it.longitude, it.latitude)
        })
    }
}