code: def testRun(self, steps=10, observation="RGB_INTERLEAVED"):
      env = deepmind_lab.Lab("lt_chasm", [observation])
      env.reset()
  
      for _ in six.moves.range(steps):
          obs = env.observations()
          action = np.zeros((7,), dtype=np.intc)
          reward = env.step(action, num_steps=4)
  
          self.assertEqual(obs[observation].shape, (240, 320, 3))
          self.assertEqual(reward, 0.0)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from absl.testing import absltest
  import numpy
  import six
  import deepmind_lab
label_desc: Use image node_id 6 for calling the DeepMindLabTest obj's underlying member method code with example usage: obj.testRun(steps, observation) without return types