code: public void logf(String loggerFqcn, Level level, Throwable t, String format, Object... params) {
          doLogf(level, loggerFqcn, format, params, t);
      }
docs: Log a message at the given level.
  
  @param loggerFqcn the logger class name
  @param level the level
  @param t the throwable cause
  @param format the format string as per {@link String#format(String, Object...)} or resource bundle key therefor
  @param params the message parameters