final org.apache.logging.log4j.core.Logger l = (org.apache.logging.log4j.core.Logger) logger;
assertThat(l.getLevel(), is(equalTo(Level.DEBUG)));
assertThat(l.filterCount(), is(equalTo(1)));
final Iterator<Filter> iterator = l.getFilters();
assertThat(iterator.hasNext(), is(true));
final Filter filter = iterator.next();
assertThat(filter, is(instanceOf(ThreadContextMapFilter.class)));
final Map<String, Appender> appenders = l.getAppenders();
assertThat(appenders, is(notNullValue()));
assertThat(appenders.size(), is(equalTo(1)));
final Appender appender = appenders.get(APPENDER_NAME);