@Override
  public void removeAppender(String appenderName) {
    if ((config.getLoggerName() == null) || (config.getLoggerName().equals("log4j"))) {
      Logger.getRootLogger().removeAppender(appenderName);
      appenders.remove(appenderName);
    }
    else {
      throw new IllegalArgumentException("Logger " + config.getLoggerName() + " not suppoted.");
    }
  }