code: def test_empty_value_put(self):
      with tempfile.TemporaryDirectory() as tmpdir:
          cache = GFileCache(tmpdir)
          cache.put("foo", b"")
          self.assertEqual(cache.get("foo"), b"")
  
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 4 for calling the FileSystemCacheTest obj's underlying member method code with example usage: obj.test_empty_value_put() without return types