code: def test_missing_write(self):
      class LevelCache(object):
          def fetch(self, key, pk3_path):
              del key
              del pk3_path
              return False
  
      env = self._create_environment(LevelCache())
      with six.assertRaisesRegex(self, AttributeError, "write"):
          env.reset(episode=1, seed=123)
          env.step(self._dummy_action)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import shutil
  import six
  import tempfile
  from absl.testing import absltest
  import numpy
  import deepmind_lab
label_desc: Use image node_id 4 for calling the LevelCacheTest obj's underlying member method code with example usage: obj.test_missing_write() and returns: False