docstr: Initializes a A3CConfig instance.
file_path: ray/rllib/algorithms/a3c/a3c.py
imports: from typing import List, Optional, Union
  from ray.rllib.algorithms.algorithm import Algorithm
  from ray.rllib.algorithms.algorithm_config import AlgorithmConfig, NotProvided
  from ray.rllib.utils.annotations import override
  from ray.rllib.utils.deprecation import ALGO_DEPRECATION_WARNING, Deprecated, deprecation_warning
label_desc: Use image node_id 1 to create a new A3CConfig object from inherited base classes: AlgorithmConfig with example: obj = A3CConfig(algo_class)