I added this line token from here map doc and its not compiling 

```
mapFragment = (SupportMapFragment) getFragmentManager().findFragmentById(R.id.supportmapfragmentj);

```

i am getting 

> 
> cannot cast android.app.Fragment to com.here.android.mpa.mapping.SupportMapFragment
> 
> 
> 

knowing that my fragment xml is as follow 

```
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MapGuiTestActivityJ">

<fragment
        class="com.here.android.mpa.mapping.SupportMapFragment"
        android:id="@+id/supportmapfragmentj"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</android.support.constraint.ConstraintLayout>

```