code: public void setIconSize(int size){
          mEmptyIconSize = size;
          int width = mEmptyIconSize == -1 ? WRAP_CONTENT : mEmptyIconSize;
          int height = mEmptyIconSize == -1 ? WRAP_CONTENT : mEmptyIconSize;
          LinearLayout.LayoutParams iconParams = new LinearLayout.LayoutParams(width, height);
          mIcon.setLayoutParams(iconParams);
      }
docs: Set the size of the icon in the center of the view
  
  @param size      the pixel size of the icon in the center