class_docstr: A test environment decorator class.
  
  This class provides additional functionality used for testing:
    - Accumulating reward over multiple frames.
    - Accumulating events over multiple frames.
    - Collecting RGB observations and saving them to image files.
class_docstr_tok: ["A","test","environment","decorator","class",".","This","class","provides","additional","functionality","used","for","testing",":","-","Accumulating","reward","over","multiple","frames",".","-","Accumulating","events","over","multiple","frames",".","-","Collecting","RGB","observations","and","saving","them","to","image","files","."]
docstr: Advance the environment a number of steps.
docstr_tok: ["Advance","the","environment","a","number","of","steps","."]
code: def step(self, actions, steps):
      """Advance the environment a number of steps."""
      reward = self._environment.step(actions, steps)
      observations = self._environment.observations()
      self._save_current_frame()
      self._accumulate_events(self._environment.events())
      self._reward_history.append(reward)
      return reward
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  import numpy
  from PIL import Image
label_desc: Use image node_id 2 for calling the TestEnvironmentDecorator obj's underlying member method code with example usage: obj.step(actions, steps) and returns: reward