code: def get_forks(self, repository_name_or_id, collection_id, project=None, include_links=None):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          if repository_name_or_id is not None:
              route_values['repositoryNameOrId'] = self._serialize.url('repository_name_or_id', repository_name_or_id, 'str')
          if collection_id is not None:
              route_values['collectionId'] = self._serialize.url('collection_id', collection_id, 'str')
          query_parameters = {}
          if include_links is not None:
              query_parameters['includeLinks'] = self._serialize.query('include_links', include_links, 'bool')
          response = self._send(http_method='GET',
                                location_id='158c0340-bf6f-489c-9625-d572a1480d57',
                                version='5.1-preview.1',
                                route_values=route_values,
                                query_parameters=query_parameters)
          return self._deserialize('[GitRepositoryRef]', self._unwrap_collection(response))
docs: GetForks.
          [Preview API] Retrieve all forks of a repository in the collection.
          :param str repository_name_or_id: The name or ID of the repository.
          :param str collection_id: Team project collection ID.
          :param str project: Project ID or project name
          :param bool include_links: True to include links.
          :rtype: [GitRepositoryRef]