code: def step(self, actions, steps):
      self.last_actions = actions
      self.last_steps = steps
      self._frame_index += 1
      return self.test_rewards[self._frame_index - 1]
  
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 2 for calling the EnvironmentStub obj's underlying member method code with example usage: obj.step(actions, steps) and returns: self