class_docstr: Action distribution P(a1, a2) = P(a1) * P(a2 | a1)
code: def _a2_distribution(self, a1):
      a1_vec = tf.expand_dims(tf.cast(a1, tf.float32), 1)
      _, a2_logits = self.model.action_model([self.inputs, a1_vec])
      a2_dist = Categorical(a2_logits)
      return a2_dist
  
imports: from ray.rllib.models.tf.tf_action_dist import Categorical, ActionDistribution
  from ray.rllib.models.torch.torch_action_dist import TorchCategorical, TorchDistributionWrapper
  from ray.rllib.utils.framework import try_import_tf, try_import_torch
label_desc: Use image node_id 8 for calling the BinaryAutoregressiveDistribution obj's underlying member method code with example usage: obj._a2_distribution(a1) and returns: a2_dist