Null Pointer error in ActionBarToggleJellybeanMR2

[tonespy]

I get

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setHomeAsUpIndicator(android.graphics.drawable.Drawable)' on a null object#reference

located in

public static Object setActionBarUpIndicator(Object info, Activity activity,
            Drawable drawable, int contentDescRes) {
        final ActionBar actionBar = activity.getActionBar();
        actionBar.setHomeAsUpIndicator(drawable);
        actionBar.setHomeActionContentDescription(contentDescRes);
        return info;
    }
    in the ActionBarToggleJellybeanMR2 class

Pointing to #actionBar.setHomeAsUpIndicator(drawable);

Any help would be appreciated. Thanks.