class_docstr: Offline Rainbow agent with BC regularization (akin to CQL).
code: def train_step(self):
      super()._train_step()
  
imports: import functools
  from absl import logging
  from dopamine.jax import losses
  from dopamine.jax.agents.full_rainbow import full_rainbow_agent
  from dopamine.jax.agents.rainbow import rainbow_agent
  from dopamine.labs.offline_rl import fixed_replay
  from dopamine.labs.offline_rl.rlu_tfds import tfds_replay
  import gin
  import jax
  import jax.numpy
  import numpy
  import optax
  import tensorflow
label_desc: Use image node_id 7 for calling the OfflineJaxRainbowAgent obj's underlying member method code with example usage: obj.train_step() without return types