code: def test_pin_empty():
      t = torch.tensor([])
      assert not t.is_pinned()
  
      # Empty tensors will not be pinned or unpinned. It's a no-op.
      # This is also the default behavior in PyTorch.
      # We just check that it won't raise an error.
      nd = dgl.utils.pin_memory_inplace(t)
      assert not t.is_pinned()
  
file_path: dgl/tests/python/pytorch/utils/test_pin_memory.py
imports: import backend
  import dgl
  import pytest
  import torch
label_desc: Use image node_id 5 for calling a global function with example usage: test_pin_empty() without return types