public String doLayout(ILoggingEvent event) {
    if (!isStarted()) {
      return CoreConstants.EMPTY_STRING;
    }
    return writeLoopOnConverters(event);
  }
@Test
  public void testWithLettersComingFromLog4j() {
    // Letters: p = level and c = logger
    pl.setPattern("%d %p [%t] %c{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
    String regex = ClassicTestConstants.ISO_REGEX + " INFO " + MAIN_REGEX
            + " c.q.l.c.pattern.ConverterTest - Some message\\s*";
    assertThat(val, matchesPattern(regex));
  }