code: public static LoggerConfig of(AbstractLogger<?> fluentLogger) {
      // TODO(dbeaumont): Revisit if/when Flogger supports anonymous loggers.
      checkArgument(fluentLogger.getName() != null,
          "cannot obtain configuration for an anonymous logger");
      return getConfig(fluentLogger.getName());
    }
docs: Returns a configuration instance suitable for the given (non anonymous) fluent logger.
  
  <p>This method obtains and wraps the underlying logger associated with the given logger,
  retaining a strong reference and making it safe to use for persistent configuration changes.
  
  @param fluentLogger the name of the logger to be configured via this API.