public String doLayout(ILoggingEvent event) {
    if (!isStarted()) {
      return CoreConstants.EMPTY_STRING;
    }
    return writeLoopOnConverters(event);
  }
@Test
  public void contextProperty() {
    pl.setPattern("%property{a}");
    pl.start();
    lc.putProperty("a", "b");

    String val = pl.doLayout(getEventObject());
    assertEquals("b", val);
  }