code: public SwipeBack setDividerAsShadowColor(int color) {
  		GradientDrawable.Orientation orientation = getDividerOrientation();
  
  		final int endColor = color & 0x00FFFFFF;
  		GradientDrawable gradient = new GradientDrawable(orientation,
  				new int[] {
  				color,
  				endColor,
  		});
  
  		setDivider(gradient);
  
  		return this;
  	}
docs: Sets the color of the divider, if you have set the option to use a shadow
  gradient as divider
  
  You must enable the divider by calling
  {@link #setDividerEnabled(boolean)}
  
  @param color
  The color of the divider shadow.