WARN,
        /** Error */
        ERROR,
        /** Fatal */
        FATAL,
    }

    /** Factory for LoggerAdapter */
    protected static final LoggerAdapterFactory factory = getLoggerAdapterFactory();

    /** Map of loggers keyed by class */
    protected static final Map<Class<?>, Logger> loggers = newHashMap();

    /** Flag indicating initialization is complete. */
    private static boolean initialized;