 pattern.      * The constructor first sets the locale, then parses the pattern and      * creates a list of subformats for the format elements contained in it.      * Patterns and their interpretation are specified in the      * <a href="#patterns">class description</a>.      *      * @param pattern the pattern for this message format      * @exception IllegalArgumentException if the pattern is invalid      * @exception NullPointerException if {@code pattern} is      *            {@code null}      */     