code: def _filter_attrs(self, feature, request):
          
          if 'attrs' in request.params:
              attrs = request.params['attrs'].split(',')
              props = feature.properties
              new_props = {}
              for name in attrs:
                  if name in props:
                      new_props[name] = props[name]
              feature.properties = new_props
          if asbool(request.params.get('no_geom', False)):
              feature.geometry = None
          return feature
docs: Remove some attributes from the feature and set the geometry to None
              in the feature based ``attrs`` and the ``no_geom`` parameters.