code: public void setShadow(float radius, float dx, float dy, int color) {
  		shadowRadius = radius;
  		shadowDx = dx;
  		shadowDy = dy;
  		shadowColor = color;
  		updateShadow();
  	}
docs: Enables a dark shadow for this CircularImageView.
  If the radius is set to 0, the shadow is removed.
  @param radius Radius for the shadow to extend to.
  @param dx Horizontal shadow offset.
  @param dy Vertical shadow offset.
  @param color The color of the shadow to apply.