public String convert(ILoggingEvent le) {
        List<Marker> markers = le.getMarkerList();
        if (markers == null || markers.isEmpty()) {
            return EMPTY;
        }
        int size = markers.size();

        if (size == 1)
            return markers.get(0).toString();

        StringBuffer buf = new StringBuffer(32);
        for (int i = 0; i < size; i++) {
            if (i != 0)
                buf.append(' ');
            Marker m = markers.get(i);
            buf.append(m.toString());
        }
        return buf.toString();

    }
@Test
    public void testWithSeveralChildMarker() {
        Marker marker = markerFactory.getMarker("testParent");
        marker.add(markerFactory.getMarker("child1"));
        marker.add(markerFactory.getMarker("child2"));
        marker.add(markerFactory.getMarker("child3"));

        String result = converter.convert(createLoggingEvent(marker));

        assertEquals("testParent [ child1, child2, child3 ]", result);
    }