[Graphbolt]Fix docstring example (#6328)

python/dgl/graphbolt/impl/neighbor_sampler.py

@@ -61,18 +61,15 @@ class NeighborSampler(SubgraphSampler):
         >>> indptr = torch.LongTensor([0, 2, 4, 5, 6, 7 ,8])
         >>> indices = torch.LongTensor([1, 2, 0, 3, 5, 4, 3, 5])
         >>> graph = gb.from_csc(indptr, indices)
-        >>> data_format = gb.LinkPredictionEdgeFormat.INDEPENDENT
         >>> node_pairs = torch.LongTensor([[0, 1], [1, 2]])
         >>> item_set = gb.ItemSet(node_pairs, names="node_pairs")
         >>> item_sampler = gb.ItemSampler(
             ...item_set, batch_size=1,
             ...)
         >>> neg_sampler = gb.UniformNegativeSampler(
-            ...item_sampler, 2, data_format, graph)
-        >>> fanouts = [torch.LongTensor([5]), torch.LongTensor([10]),
-            ...torch.LongTensor([15])]
+            ...item_sampler, graph, 2)
         >>> subgraph_sampler = gb.NeighborSampler(
-            ...neg_sampler, graph, fanouts)
+            ...neg_sampler, graph, [5, 10, 15])
         >>> for data in subgraph_sampler:
             ... print(data.compacted_node_pairs)
             ... print(len(data.sampled_subgraphs))