NullPointerException - Android Google Maps Street View

I am trying to display a street view in a fragment.

public class StreetDisplay extends Fragment implements OnStreetViewPanoramaReadyCallback{

SupportStreetViewPanoramaFragment streetFrag;

static final LatLng PosOne = new LatLng(43.771925, -79.512460);

@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.street_display, container, false);
    initialize();
    return v;

}

private void initialize() {

    streetFrag =
            (SupportStreetViewPanoramaFragment) getFragmentManager()
                    .findFragmentById(R.id.street);
    streetFrag.getStreetViewPanoramaAsync(this);
}

//this method is needed for using a ViewPager swiping feature
public static StreetDisplay newInstance(){
    StreetDisplay sd = new StreetDisplay();
    return sd;
}

@Override
public void onStreetViewPanoramaReady(StreetViewPanorama panorama) {
    panorama.setPosition(PosOne);
}
}

Here's the error message I get when I run my app

Process: com.example.nikhilbhaskar.mapplayground, PID: 22406
java.lang.NullPointerException
        at com.example.nikhilbhaskar.mapplayground.StreetDisplay.initialize(StreetDisplay.java:43)
        at com.example.nikhilbhaskar.mapplayground.StreetDisplay.onCreateView(StreetDisplay.java:33)

Line 33 is

initialize();

Line 43 is

streetFrag.getStreetViewPanoramaAsync(this);  

I am not sure what the problem is - Can you help?