code: private static String format(final String aBundleName, final String aMessageKey, final Object... aVarargs) {
          return format(null, aBundleName, aMessageKey, aVarargs);
      }
docs: Constructs our I18n exception message using the supplied bundle name.
  
  @param aBundleName A name of a bundle in which to look up the supplied key.
  @param aMessageKey A key value to look up in the <code>ResourceBundle</code>.
  @param aVarargs Additional details to use in formatting the message.
  @return A formatted exception message