public void setChecked(final PluginDownloader downloader, final boolean checked) {
   if (checked) {
     getSkippedPlugins().remove(downloader.getPluginId());
   } else {
     getSkippedPlugins().add(downloader.getPluginId());
   }
   for (Listener listener : myListeners) {
     listener.stateChanged();
   }
 }
 public boolean isChecked(final PluginDownloader downloader) {
   return !getSkippedPlugins().contains(downloader.getPluginId());
 }