code: def __init__(self, gpt2_lm_model):
      self._gpt2_lm_model = gpt2_lm_model
      self._layout = self._gpt2_lm_model._backbone_model.layout
  
file_path: gluon-nlp/docs/model_zoo/generation/generate_unconditional_gpt2_samples.py
imports: import os
  import mxnet
  import argparse
  from gluonnlp.utils import set_seed
  from gluonnlp.sequence_sampler import BeamSearchSampler, BaseStepDecoder
  from gluonnlp.models.gpt2 import GPT2ForLM, list_pretrained_gpt2, get_pretrained_gpt2
label_desc: Use image node_id 1 to create a new GPT2Decoder object from inherited base classes: BaseStepDecoder with example: obj = GPT2Decoder(gpt2_lm_model)