code: func (m *GormAreaRepository) Root(ctx context.Context, spaceID uuid.UUID) (*Area, error) {
  	defer goa.MeasureSince([]string{"goa", "db", "Area", "root"}, time.Now())
  	var rootArea []Area
  
  	rootArea, err := m.Query(FilterBySpaceID(spaceID), func(db *gorm.DB) *gorm.DB {
  		return db.Where("space_id = ? AND nlevel(path)=1", spaceID)
  	})
  
  	if len(rootArea) != 1 {
  		return nil, errors.NewInternalError(ctx, errs.Errorf("single Root area not found for space %s", spaceID))
  	}
  	if err != nil {
  		return nil, err
  	}
  	return &rootArea[0], nil
  }
docs: // Root fetches the Root Areas inside a space.