code: def queue_delete_project(self, project_id):
          
          route_values = {}
          if project_id is not None:
              route_values['projectId'] = self._serialize.url('project_id', project_id, 'str')
          response = self._send(http_method='DELETE',
                                location_id='603fe2ac-9723-48b9-88ad-09305aa6c6e1',
                                version='5.1-preview.4',
                                route_values=route_values)
          return self._deserialize('OperationReference', response)
docs: QueueDeleteProject.
          [Preview API] Queues a project to be deleted. Use the [GetOperation](../../operations/operations/get) to periodically check for delete project status.
          :param str project_id: The project id of the project to delete.
          :rtype: :class:`<OperationReference> <azure.devops.v5_1.core.models.OperationReference>`