code: def test_list_dir(self):
      for i in range(10):
          with gfile.GFile("ram://a/b/%d.txt" % i, "w") as f:
              f.write("")
          with gfile.GFile("ram://c/b/%d.txt" % i, "w") as f:
              f.write("")
  
      matches = ["%d.txt" % i for i in range(10)]
      self.assertEqual(gfile.ListDirectory("ram://a/b/"), matches)
  
file_path: tensorflow-upstream/tensorflow/core/platform/ram_file_system_test.py
imports: import platform
  from tensorflow.python.compat import v2_compat
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import test_util
  from tensorflow.python.lib.io import file_io
  from tensorflow.python.module import module
  from tensorflow.python.platform import gfile
  from tensorflow.python.platform import test
  from tensorflow.python.saved_model import saved_model
label_desc: Use image node_id 5 for calling the RamFilesystemTest obj's underlying member method code with example usage: obj.test_list_dir() without return types