code: private void adaptShadow() {
          if (getSize() == Size.NORMAL) {
              setBackgroundResource(R.drawable.floating_action_button_shadow_normal);
          } else if (getSize() == Size.SMALL) {
              setBackgroundResource(R.drawable.floating_action_button_shadow_small);
          } else {
              setBackgroundResource(R.drawable.floating_action_button_shadow_large);
          }
      }
docs: Adapts the shadow of the floating action button, depending on its size.