code: def get_branches(self, repository_id, project=None, base_version_descriptor=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')
          query_parameters = {}
          if base_version_descriptor is not None:
              if base_version_descriptor.version_type is not None:
                  query_parameters['baseVersionDescriptor.versionType'] = base_version_descriptor.version_type
              if base_version_descriptor.version is not None:
                  query_parameters['baseVersionDescriptor.version'] = base_version_descriptor.version
              if base_version_descriptor.version_options is not None:
                  query_parameters['baseVersionDescriptor.versionOptions'] = base_version_descriptor.version_options
          response = self._send(http_method='GET',
                                location_id='d5b216de-d8d5-4d32-ae76-51df755b16d3',
                                version='5.0',
                                route_values=route_values,
                                query_parameters=query_parameters)
          return self._deserialize('[GitBranchStats]', self._unwrap_collection(response))
docs: GetBranches.
          Retrieve statistics about all branches within a repository.
          :param str repository_id: The name or ID of the repository.
          :param str project: Project ID or project name
          :param :class:`<GitVersionDescriptor> <azure.devops.v5_0.git.models.GitVersionDescriptor>` base_version_descriptor: Identifies the commit or branch to use as the base.
          :rtype: [GitBranchStats]