code: public void fireRemoveAppenderEvent(final Category logger,
                                          final Appender appender) {
         if (repo instanceof Hierarchy) {
             ((Hierarchy) repo).fireRemoveAppenderEvent(logger, appender);
         }
      }
docs: Requests that a appender removed event be sent to any registered
  {@link LoggerEventListener}.
  @param logger The logger from which the appender was removed.
  @param appender The appender removed from the logger.