com.esri.arcgisruntime.mapping.view.MapView.setMap Attempt to invoke virtual method on a null object reference

[ScottBing2]

I am attempting to execute thecode where the error occur Kotlin sample code for Find_Route and I get the following error at line 71 in the code:    Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.esri.arcgisruntime.mapping.view.MapView.setMap(com.esri.arcgisruntime.mapping.ArcGISMap)' on a null object reference.

Here is the code where the error occurs:

<

// create a map with the basemap
val map = ArcGISMap().apply {
    // set the basemap with the vector tiled layer from a service URL
    basemap = Basemap(
        ArcGISVectorTiledLayer(getString(R.string.navigation_vector))
    )
}

mapView.apply {
    // set the map to be displayed in this view
    this.map = map   <<<<  Error occurs here...
    // set initial viewpoint to San Diego
    setViewpoint(Viewpoint(32.7157, -117.1611, 200000.0))
    // ensure the floating action button moves to be above the attribution view
    addAttributionViewLayoutChangeListener { _, _, _, _, bottom, _, _, _, oldBottom ->
        val heightDelta = bottom - oldBottom
        (directionFab.layoutParams as ConstraintLayout.LayoutParams).bottomMargin += heightDelta
    }
    mapView.graphicsOverlays.add(graphicsOverlay)
}/>

Error occurs at highlighted code in red font. 

[CodeDynode]

Hello,

I would like to suggest you please use 
'mapView.map = map'

instead of

'this.map = map'.

I hope this will resolve you're the issue.

Thanks