code: def update_pull_request_iteration_statuses(self, patch_document, repository_id, pull_request_id, iteration_id, project=None):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          if repository_id is not None:
              route_values['repositoryId'] = self._serialize.url('repository_id', repository_id, 'str')
          if pull_request_id is not None:
              route_values['pullRequestId'] = self._serialize.url('pull_request_id', pull_request_id, 'int')
          if iteration_id is not None:
              route_values['iterationId'] = self._serialize.url('iteration_id', iteration_id, 'int')
          content = self._serialize.body(patch_document, '[JsonPatchOperation]')
          self._send(http_method='PATCH',
                     location_id='75cf11c5-979f-4038-a76e-058a06adf2bf',
                     version='5.1-preview.1',
                     route_values=route_values,
                     content=content,
                     media_type='application/json-patch+json')
docs: UpdatePullRequestIterationStatuses.
          [Preview API] Update pull request iteration statuses collection. The only supported operation type is `remove`.
          :param :class:`<[JsonPatchOperation]> <azure.devops.v5_1.git.models.[JsonPatchOperation]>` patch_document: Operations to apply to the pull request statuses in JSON Patch format.
          :param str repository_id: The repository ID of the pull request’s target branch.
          :param int pull_request_id: ID of the pull request.
          :param int iteration_id: ID of the pull request iteration.
          :param str project: Project ID or project name