code: func (r *GormWorkItemRepository) CheckExists(ctx context.Context, workitemID uuid.UUID) error {
  	defer goa.MeasureSince([]string{"goa", "db", "workitem", "exists"}, time.Now())
  	return repository.CheckExists(ctx, r.db, workitemTableName, workitemID)
  }
docs: // CheckExists returns nil if the given ID exists otherwise returns an error