code: def get_billable_items(self):
          
          items = []
          for obj in self.context.getBillableItems():
              if self.is_profile(obj):
                  items.append({
                      "obj": obj,
                      "title": obj.Title(),
                      "vat": obj.getAnalysisProfileVAT(),
                      "price": self.format_price(obj.getAnalysisProfilePrice()),
                  })
              if self.is_analysis(obj):
                  items.append({
                      "obj": obj,
                      "title": obj.Title(),
                      "vat": obj.getVAT(),
                      "price": self.format_price(obj.getPrice()),
                  })
          return items
docs: Return a list of billable items