class_docstr: Dummy Env class for testing.
code: def step(self, action):
      del action
      info = {
          "control_mask": self._step % 2 == 0,
          "discount_mask": self._step % 3 == 0,
      }
      self._step += 1
      return np.ones((2,)), 0.0, False, info
  
imports: import os
  from absl.testing import absltest
  import gym
  import numpy
  from trax import test_utils
  from trax.rl import task
label_desc: Use image node_id 2 for calling the DummyEnv obj's underlying member method code with example usage: obj.step(action) and returns: np,  int,  False,  info