code: public static SwipeBack attach(Activity activity, Type type, Position position, SwipeBackTransformer transformer) {
  		return attach(activity, type, position, DRAG_WINDOW, transformer);
  	}
docs: Attaches the SwipeBack to the Activity.
  
  @param activity
  The activity the swipe back will be attached to.
  @param type
  The {@link SwipeBack.Type} of the drawer.
  @param position
  Where to position the swipe back.
  @param transformer
  @return The created SwipeBack instance.