chore: import upstream snapshot with attribution

tests/python/pytorch/test_multiprocessing-ipc.py

@@ -0,0 +1,26 @@
+import os
+import unittest
+
+import dgl
+
+import torch as th
+import torch.multiprocessing as mp
+
+
+def sub_ipc(g):
+    print(g)
+    return g
+
+
+@unittest.skipIf(os.name == "nt", reason="Do not support windows yet")
+def test_torch_ipc():
+    g = dgl.graph(([0, 1, 2], [1, 2, 3]))
+    ctx = mp.get_context("spawn")
+    p = ctx.Process(target=sub_ipc, args=(g,))
+
+    p.start()
+    p.join()
+
+
+if __name__ == "__main__":
+    test_torch_ipc()