code: def observations(self):
      return self.test_observations[self._frame_index]
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import tempfile
  from absl.testing import absltest
  import numpy
  import six
  from PIL import Image
  from python.tests.utils import test_environment_decorator
label_desc: Use image node_id 4 for calling the EnvironmentStub obj's underlying member method code with example usage: obj.observations() and returns: self