public String getDescription()
  {
    if ( fullDescription == null )
    {
      if ( description == null || isExtensionListInDescription() )
      {
        fullDescription = description == null ? "(" : description + " (" ;
        // build the description from the extension list
        Enumeration extensions = filters.keys() ;
        if ( extensions != null )
        {
          fullDescription += "." + ( String ) extensions.nextElement() ;
          while ( extensions.hasMoreElements() )
          {
            fullDescription += ", ." + ( String ) extensions.nextElement() ;
          }
        }
        fullDescription += ")" ;
      }
      else
      {
        fullDescription = description ;
      }
    }
    return fullDescription ;
  }