Still do BFS when reading from ckpt without bfs roots specified.
Still do BFS when reading from ckpt without bfs roots specified.

uwsampa/grappa,buaasun/grappa,buaasun/grappa,alexfrolov/grappa,alexfrolov/grappa,alexfrolov/grappa,alexfrolov/grappa,alexfrolov/grappa,alexfrolov/grappa,buaasun/grappa,buaasun/grappa,buaasun/grappa,uwsampa/grappa,uwsampa/grappa,uwsampa/grappa,buaasun/grappa,alexfrolov/grappa,uwsampa/grappa,uwsampa/grappa,buaasun/grappa,uwsampa/grappa