code: def get_pipeline(self, project, pipeline_id, revision=None):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          if pipeline_id is not None:
              route_values['pipelineId'] = self._serialize.url('pipeline_id', pipeline_id, 'int')
          query_parameters = {}
          if revision is not None:
              query_parameters['revision'] = self._serialize.query('revision', revision, 'int')
          response = self._send(http_method='GET',
                                location_id='28e1305e-2afe-47bf-abaf-cbb0e6a91988',
                                version='5.1-preview.1',
                                route_values=route_values,
                                query_parameters=query_parameters)
          return self._deserialize('Pipeline', response)
docs: GetPipeline.
          [Preview API]
          :param str project: Project ID or project name
          :param int pipeline_id:
          :param int revision:
          :rtype: :class:`<Pipeline> <azure.devops.v5_1.pipelines.models.Pipeline>`