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