code: @Override
      protected Component doHighlight(final Component component, final ComponentAdapter adapter) {
          final Icon icon = getIcon(adapter.getValue(columnIndex));
  
          if (icon != null) {
              if (component instanceof IconAware) {
                  ((IconAware) component).setIcon(icon);
              } else if (component instanceof JLabel) {
                  ((JLabel) component).setIcon(icon);
              }
          } else {
              if (component instanceof JLabel) {
                  ((JLabel) component).setText("");
              }
          }
          return component;
      }
docs: Implementation adapted from org.jdesktop.swingx.decorator.IconHighlighter#doHighlight(Component, ComponentAdapter)