code: @Nonnull
    @Nonempty
    public static String getAsCSSURL (@Nonnull final ISimpleURL aURL, final boolean bQuoteURL)
    {
      ValueEnforcer.notNull (aURL, "URL");
  
      return getAsCSSURL (aURL.getAsStringWithEncodedParameters (), bQuoteURL);
    }
docs: Surround the passed URL with the CSS "url(...)"
  
  @param aURL
  URL to be wrapped. May not be <code>null</code>.
  @param bQuoteURL
  if <code>true</code> single quotes are added around the URL
  @return <code>url(<i>sURL</i>)</code> or <code>url('<i>sURL</i>')</code>