[GraphBolt] relocate utils (#6227)

python/dgl/graphbolt/dataloader.py

@@ -4,10 +4,11 @@ import torch.utils.data
 import torchdata.dataloader2.graph as dp_utils
 import torchdata.datapipes as dp
 
-from .datapipe_utils import datapipe_graph_to_adjlist
 from .feature_fetcher import FeatureFetcher
 from .minibatch_sampler import MinibatchSampler
 
+from .utils import datapipe_graph_to_adjlist
+
 
 class SingleProcessDataLoader(torch.utils.data.DataLoader):
     """Single process DataLoader.

python/dgl/graphbolt/utils/__init__.py

 """Utility functions for GraphBolt."""
 from .internal import *
 from .sample_utils import *
+from .datapipe_utils import *

python/dgl/graphbolt/datapipe_utils.py → python/dgl/graphbolt/utils/datapipe_utils.py

 """DataPipe utilities"""
 
+__all__ = ["datapipe_graph_to_adjlist"]
+
 
 def _get_parents(result_dict, datapipe_graph):
     for k, (v, parents) in datapipe_graph.items():