[GraphBolt] Update name used in `LegacyDataset`. (#7283)

Co-authored-by: Ubuntu <ubuntu@ip-172-31-0-133.us-west-2.compute.internal>

python/dgl/graphbolt/impl/legacy_dataset.py

@@ -33,7 +33,7 @@ class LegacyDataset(Dataset):
             for key in idx.keys():
                 item_set = ItemSet(
                     (idx[key], labels[key][idx[key]]),
-                    names=("seed_nodes", "labels"),
+                    names=("seeds", "labels"),
                 )
                 item_set_dict[key] = item_set
             return ItemSetDict(item_set_dict)
@@ -58,7 +58,7 @@ class LegacyDataset(Dataset):
 
             item_set_dict = {}
             for ntype in graph.ntypes:
-                item_set = ItemSet(graph.num_nodes(ntype), names="seed_nodes")
+                item_set = ItemSet(graph.num_nodes(ntype), names="seeds")
                 item_set_dict[ntype] = item_set
             self._all_nodes_set = ItemSetDict(item_set_dict)
 
@@ -100,21 +100,21 @@ class LegacyDataset(Dataset):
         test_labels = legacy[0].ndata["label"][legacy.test_idx]
         train_set = ItemSet(
             (legacy.train_idx, train_labels),
-            names=("seed_nodes", "labels"),
+            names=("seeds", "labels"),
         )
         validation_set = ItemSet(
             (legacy.val_idx, validation_labels),
-            names=("seed_nodes", "labels"),
+            names=("seeds", "labels"),
         )
         test_set = ItemSet(
-            (legacy.test_idx, test_labels), names=("seed_nodes", "labels")
+            (legacy.test_idx, test_labels), names=("seeds", "labels")
         )
         task = OnDiskTask(metadata, train_set, validation_set, test_set)
         tasks.append(task)
         self._tasks = tasks
 
         num_nodes = legacy[0].num_nodes()
-        self._all_nodes_set = ItemSet(num_nodes, names="seed_nodes")
+        self._all_nodes_set = ItemSet(num_nodes, names="seeds")
         features = {}
         for name in legacy[0].ndata.keys():
             tensor = legacy[0].ndata[name]

tests/python/pytorch/graphbolt/impl/test_legacy_dataset.py

@@ -12,11 +12,11 @@ def test_LegacyDataset_homo_node_pred():
     # Check tasks.
     assert len(dataset.tasks) == 1
     task = dataset.tasks[0]
-    assert task.train_set.names == ("seed_nodes", "labels")
+    assert task.train_set.names == ("seeds", "labels")
     assert len(task.train_set) == 140
-    assert task.validation_set.names == ("seed_nodes", "labels")
+    assert task.validation_set.names == ("seeds", "labels")
     assert len(task.validation_set) == 500
-    assert task.test_set.names == ("seed_nodes", "labels")
+    assert task.test_set.names == ("seeds", "labels")
     assert len(task.test_set) == 1000
     assert task.metadata["num_classes"] == 7