code: public static SwipeBack attach(Activity activity, Type type, Position position, int dragMode, SwipeBackTransformer transformer) {
  
  		SwipeBack swipeBack = createSwipeBack(activity, dragMode, position, type, transformer);
  		swipeBack.setId(R.id.sb__swipeBack);
  
  
  		switch (dragMode) {
  		case SwipeBack.DRAG_CONTENT:
  			attachToContent(activity, swipeBack);
  			break;
  
  		case SwipeBack.DRAG_WINDOW:
  			attachToDecor(activity, swipeBack);
  			break;
  
  		default:
  			throw new RuntimeException("Unknown drag mode: " + dragMode);
  		}
  
  
  		return swipeBack;
  	}
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 dragMode
  The drag mode of the drawer. Can be either
  {@link SwipeBack#DRAG_CONTENT} or
  {@link SwipeBack#DRAG_WINDOW}.
  @return The created SwipeBack instance.