code: def test_sparse(self):
      data = {"test": torch.sparse_coo_tensor(size=(2, 3))}
      local = "./tests/data/out_safe_pt_sparse.safetensors"
      with self.assertRaises(ValueError) as ctx:
          save_file(data, local)
      self.assertEqual(
          str(ctx.exception),
          "You are trying to save a sparse tensors: `['test']` which this library does not support. You can make it"
          " a dense tensor before saving with `.to_dense()` but be aware this might make a much larger file than"
          " needed.",
      )
  
imports: import sys
  import unittest
  import torch
  from safetensors import safe_open
  from safetensors.torch import load, load_file, save, save_file
label_desc: Use image node_id 10 for calling the TorchTestCase obj's underlying member method code with example usage: obj.test_sparse() without return types