code: func (c *AreaController) ShowChildren(ctx *app.ShowChildrenAreaContext) error {
  	id, err := uuid.FromString(ctx.ID)
  	if err != nil {
  		return jsonapi.JSONErrorResponse(ctx, goa.ErrNotFound(err.Error()))
  	}
  	var children []area.Area
  	err = application.Transactional(c.db, func(appl application.Application) error {
  		parentArea, err := appl.Areas().Load(ctx, id)
  		if err != nil {
  			return err
  		}
  		children, err = appl.Areas().ListChildren(ctx, parentArea)
  		return err
  	})
  	if err != nil {
  		return jsonapi.JSONErrorResponse(ctx, err)
  	}
  
  	return ctx.ConditionalEntities(children, c.config.GetCacheControlAreas, func() error {
  		res := &app.AreaList{}
  		res.Data = ConvertAreas(c.db, ctx.Request, children, addResolvedPath)
  		return ctx.OK(res)
  	})
  }
docs: // ShowChildren runs the show-children action