code: def create_user(self, creation_context, group_descriptors=None):
          
          query_parameters = {}
          if group_descriptors is not None:
              group_descriptors = ",".join(group_descriptors)
              query_parameters['groupDescriptors'] = self._serialize.query('group_descriptors', group_descriptors, 'str')
          content = self._serialize.body(creation_context, 'GraphUserCreationContext')
          response = self._send(http_method='POST',
                                location_id='005e26ec-6b77-4e4f-a986-b3827bf241f5',
                                version='5.1-preview.1',
                                query_parameters=query_parameters,
                                content=content)
          return self._deserialize('GraphUser', response)
docs: CreateUser.
          [Preview API] Materialize an existing AAD or MSA user into the VSTS account.
          :param :class:`<GraphUserCreationContext> <azure.devops.v5_1.graph.models.GraphUserCreationContext>` creation_context: The subset of the full graph user used to uniquely find the graph subject in an external provider.
          :param [str] group_descriptors: A comma separated list of descriptors of groups you want the graph user to join
          :rtype: :class:`<GraphUser> <azure.devops.v5_1.graph.models.GraphUser>`