code: def test_prefetch_loader(device):
      data = [torch.randn(5, 5) for _ in range(10)]
  
      loader = PrefetchLoader(data, device=device)
      assert str(loader).startswith("PrefetchLoader")
      assert len(loader) == 10
  
      for i, batch in enumerate(loader):
          assert batch.device == device
          assert torch.equal(batch.cpu(), data[i])
  
imports: import torch
  from torch_geometric.loader import NeighborLoader, PrefetchLoader
  from torch_geometric.nn import GraphSAGE
  from torch_geometric.testing import withCUDA
label_desc: Use image node_id 1 for calling a global function with example usage: test_prefetch_loader(device) without return types