code: def package_repositories(self):
          
          if self._package_repository_manager is None:
              self._package_repository_manager = PackageRepositoryManager(session=self._session)
          return self._package_repository_manager
docs: Property for accessing :class:`PackageRepositoryManager` instance, which is used to manage package repos.
  
          :rtype: yagocd.resources.package_repository.PackageRepositoryManager