category.getLogger().addAppender(appender);
category.error("Test Message");
final List<String> msgs = appender.getMessages();
assertTrue("Incorrect number of messages. Expected 1 got " + msgs.size(), msgs.size() == 1);
final String msg = msgs.get(0);
appender.clear();
final String threadName = Thread.currentThread().getName();
final String expected = "ERROR o.a.l.CategoryTest [" + threadName + "] Test Message" + Constants.LINE_SEP;
assertTrue("Incorrect message \"" + msg + "\"" + " expected \"" + expected +"\"", msg.endsWith(expected));
}