code: func With(ctx context.Context, opts ...func(logrus.Fields)) context.Context {
  	logger := FromContext(ctx)
  
  	fields := make(logrus.Fields)
  	for _, opt := range opts {
  		opt(fields)
  	}
  	logger = logger.WithFields(fields)
  
  	return context.WithValue(ctx, loggerKey, logger)
  }
docs: // With Adds fields