How to add gravity to drawer?

Hi, Thanks for such a nice library.

I had an issue. 
I've added 4 items to a drawer. Those items are showing in the center of the drawer. I want it to show right below the header in a vertical sequence. I've tried adding **android:layout_gravity="top" android:gravity="top"** to xml DuoDrawerLayout but no use. Please let me know how to resolve it.