code: def update_group(self, group_descriptor, patch_document):
          
          route_values = {}
          if group_descriptor is not None:
              route_values['groupDescriptor'] = self._serialize.url('group_descriptor', group_descriptor, 'str')
          content = self._serialize.body(patch_document, '[JsonPatchOperation]')
          response = self._send(http_method='PATCH',
                                location_id='ebbe6af8-0b91-4c13-8cf1-777c14858188',
                                version='5.0-preview.1',
                                route_values=route_values,
                                content=content,
                                media_type='application/json-patch+json')
          return self._deserialize('GraphGroup', response)
docs: UpdateGroup.
          [Preview API] Update the properties of a VSTS group.
          :param str group_descriptor: The descriptor of the group to modify.
          :param :class:`<[JsonPatchOperation]> <azure.devops.v5_0.graph.models.[JsonPatchOperation]>` patch_document: The JSON+Patch document containing the fields to alter.
          :rtype: :class:`<GraphGroup> <azure.devops.v5_0.graph.models.GraphGroup>`