code: @Override
      public void trace(String msg, Throwable t) {
          logger.log(FQCN, traceCapable ? Level.TRACE : Level.DEBUG, msg, t);
      }
docs: Log an exception (throwable) at level TRACE with an accompanying message.
  
  @param msg
  the message accompanying the exception
  @param t
  the exception (throwable) to log