public String convert(ILoggingEvent le) {
    List<Marker> markers = le.getMarkers();
    if (markers == null || markers.isEmpty()) {
      return EMPTY;
    } else {
      return markers.toString();
    }
  }
@Test
  public void testWithOneChildMarker() {
    Marker marker = markerFactory.getMarker("test");
    marker.add(markerFactory.getMarker("child"));
    
    String result = converter.convert(createLoggingEvent(marker));
    
    assertEquals("[test [ child ]]", result);
  }