code: public void setShadowRadius(int dimenResId) {
          int shadowRadius = getResources().getDimensionPixelSize(dimenResId);
          if (mShadowRadius != shadowRadius) {
              mShadowRadius = shadowRadius;
              requestLayout();
              updateBackground();
          }
      }
docs: Sets the shadow radius of the <b>FloatingActionButton</b> and invalidates its layout.
  
  @param dimenResId the resource identifier of the dimension