code: def test_empty_key_put(self):
      with tempfile.TemporaryDirectory() as tmpdir:
          cache = GFileCache(tmpdir)
          with self.assertRaisesRegex(
              ValueError, r"key cannot be empty"
          ):
              cache.put("", b"bar")
  
file_path: jax/tests/gfile_cache_test.py
imports: import tempfile
  import threading
  from absl.testing import absltest
  from jax._src.gfile_cache import GFileCache
  import jax._src.test_util
label_desc: Use image node_id 5 for calling the FileSystemCacheTest obj's underlying member method code with example usage: obj.test_empty_key_put() without return types