code: def get(context, request, key=None):
      
      registry_records = api.get_registry_records_by_keyword(key)
  
      # Prepare batch
      size = req.get_batch_size()
      start = req.get_batch_start()
      batch = api.make_batch(registry_records, size, start)
  
      return {
          "pagesize": batch.get_pagesize(),
          "next": batch.make_next_url(),
          "previous": batch.make_prev_url(),
          "page": batch.get_pagenumber(),
          "pages": batch.get_numpages(),
          "count": batch.get_sequence_length(),
          "items": [registry_records],
          "url": api.url_for("senaite.jsonapi.v1.registry", key=key),
      }
docs: Return all registry items if key is None, otherwise try to fetch the registry key