public String doLayout(ILoggingEvent event) {
        if (!isStarted()) {
            return CoreConstants.EMPTY_STRING;
        }
        return writeLoopOnConverters(event);
    }
@Test
    public void testOK() {
        pl.setPattern("%d %le [%t] %lo{30} - %m%n");
        pl.start();
        String val = pl.doLayout(getEventObject());
        // 2006-02-01 22:38:06,212 INFO [main] c.q.l.pattern.ConverterTest - Some
        // message
        // 2010-12-29 19:04:26,137 INFO [pool-1-thread-47] c.q.l.c.pattern.ConverterTest
        // - Some message
        String regex = ISO_REGEX + " INFO " + MAIN_REGEX + " c.q.l.c.pattern.ConverterTest - Some message\\s*";

        assertTrue( val.matches(regex), "val=" + val);
    }