code: def get_descriptor(self, storage_key):
          
          route_values = {}
          if storage_key is not None:
              route_values['storageKey'] = self._serialize.url('storage_key', storage_key, 'str')
          response = self._send(http_method='GET',
                                location_id='048aee0a-7072-4cde-ab73-7af77b1e0b4e',
                                version='5.1-preview.1',
                                route_values=route_values)
          return self._deserialize('GraphDescriptorResult', response)
docs: GetDescriptor.
          [Preview API] Resolve a storage key to a descriptor
          :param str storage_key: Storage key of the subject (user, group, scope, etc.) to resolve
          :rtype: :class:`<GraphDescriptorResult> <azure.devops.v5_1.graph.models.GraphDescriptorResult>`