code: func (c *Manager) GetCategories(ctx context.Context) ([]Category, error) {
  	ids, err := c.ListCategories(ctx)
  	if err != nil {
  		return nil, fmt.Errorf("list categories: %s", err)
  	}
  
  	var categories []Category
  	for _, id := range ids {
  		category, err := c.GetCategory(ctx, id)
  		if err != nil {
  			return nil, fmt.Errorf("get category %s: %s", id, err)
  		}
  
  		categories = append(categories, *category)
  
  	}
  	return categories, nil
  }
docs: // GetCategories fetches an array of category information in the system.