code: def __init__(self, env, model, nsteps):
      super().__init__(env=env, model=model, nsteps=nsteps)
      assert isinstance(
          env.action_space, spaces.Discrete
      ), "This ACER implementation works only with discrete action spaces!"
      assert isinstance(env, VecFrameStack)
  
      self.nact = env.action_space.n
      nenv = self.nenv
      self.nbatch = nenv * nsteps
      self.batch_ob_shape = (
          nenv * (nsteps + 1),
      ) + env.observation_space.shape
  
      self.obs = env.reset()
      self.obs_dtype = env.observation_space.dtype
      self.ac_dtype = env.action_space.dtype
      self.nstack = self.env.nstack
      self.nc = self.batch_ob_shape[-1] // self.nstack
  
file_path: baselines/baselines/acer/runner.py
imports: import numpy
  from baselines.common.runners import AbstractEnvRunner
  from baselines.common.vec_env.vec_frame_stack import VecFrameStack
  from gym import spaces
label_desc: Use image node_id 1 to create a new Runner object from inherited base classes: AbstractEnvRunner with example: obj = Runner(env, model, nsteps)