code: def _get_items(self, request):
          
          if request.gpd_iterator is None:
              self.gpd_iterator = GeopediaFeatureIterator(request.layer, bbox=request.bbox, base_url=self.base_url,
                                                          gpd_session=request.gpd_session)
          else:
              self.gpd_iterator = request.gpd_iterator
  
          field_iter = self.gpd_iterator.get_field_iterator(request.image_field_name)
          items = []
  
          for field_items in field_iter:  # an image field can have multiple images
  
              for item in field_items:
                  if not item['mimeType'].startswith('image/'):
                      continue
  
                  mime_type = MimeType.from_string(item['mimeType'][6:])
  
                  if mime_type is request.image_format:
                      items.append(item)
  
          return items
docs: Collects data from Geopedia layer and returns list of features