code: def __post_init__(self):
      assert self.generator is not None, "generator must be specified"
  
      if self.gen_kwargs is None:
          self.gen_kwargs = {}
  
file_path: datasets/src/datasets/packaged_modules/generator/generator.py
imports: from dataclasses import dataclass
  from typing import Callable, Optional
  import datasets
label_desc: Use image node_id 1 for calling the GeneratorConfig obj's underlying member method code with example usage: obj.__post_init__() without return types