code: def test_set_get_stream():
      current_stream = torch.cuda.current_stream()
      # test setting another stream
      s = torch.cuda.Stream(device=F.ctx())
      torch.cuda.set_stream(s)
      assert (
          to_dgl_stream_handle(s).value
          == _dgl_get_stream(to_dgl_context(F.ctx())).value
      )
      # revert to default stream
      torch.cuda.set_stream(current_stream)
  
file_path: dgl/tests/python/pytorch/test_ffi-stream.py
imports: import unittest
  from statistics import mean
  import backend
  import dgl
  import dgl.ndarray
  import dgl.ops
  import numpy
  import torch
  from dgl import rand_graph
  from dgl._ffi.streams import _dgl_get_stream, to_dgl_stream_handle
  from dgl.utils import to_dgl_context
label_desc: Use image node_id 3 for calling a global function with example usage: test_set_get_stream() without return types