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*";

    assertThat(val, matchesPattern(regex));
  }