private void format(Object[] arguments, Map<String, Object> argsMap,
                        AppendableWrapper dest, FieldPosition fp) {
        if (arguments != null && msgPattern.hasNamedArguments()) {
            throw new IllegalArgumentException(
                "This method is not available in MessageFormat objects " +
                "that use alphanumeric argument names.");
        }
        format(0, null, arguments, argsMap, dest, fp);
    }
private void format ( Object [ ] arguments , Map < String , Object > argsMap , AppendableWrapper dest , FieldPosition fp ) { if ( arguments != null && msgPattern . hasNamedArguments ( ) ) { throw new IllegalArgumentException ( "This method is not available in MessageFormat objects " + "that use alphanumeric argument names." ) ; } format ( 0 , null , arguments , argsMap , dest , fp ) ; }
Internal routine used by format.

@throws IllegalArgumentException if an argument in the
<code>arguments</code> map is not of the type
expected by the format element(s) that use it.