class_docstr: A class containing all of the functions supporting generation, to be used as a mixin in
  :class:`~transformers.PreTrainedModel`.
class_docstr_tok: ["A","class","containing","all","of","the","functions","supporting","generation",",","to","be","used","as","a","mixin","in",":","class",":","`","~transformers.PreTrainedModel","`","."]
code: def _get_pad_token_id(
      self, pad_token_id: int = None, eos_token_id: int = None
  ) -> int:
      if pad_token_id is None and eos_token_id is not None:
          logger.rank_zero_warning(
              f"Setting `pad_token_id` to `eos_token_id`:{eos_token_id} for open-end generation."
          )
          pad_token_id = eos_token_id
      return pad_token_id
  
imports: from dataclasses import dataclass
  from typing import Any, Callable, Dict, Iterable, List, Optional, Tuple, Union
  from .file_utils import ModelOutput
  from .generation_beam_search import BeamScorer, BeamSearchScorer
  from .generation_logits_process import EncoderNoRepeatNGramLogitsProcessor, ForcedBOSTokenLogitsProcessor, ForcedEOSTokenLogitsProcessor, HammingDiversityLogitsProcessor, InfNanRemoveLogitsProcessor, LogitsProcessorList, MinLengthLogitsProcessor, NoBadWordsLogitsProcessor, NoRepeatNGramLogitsProcessor, PrefixConstrainedLogitsProcessor, RepetitionPenaltyLogitsProcessor, TemperatureLogitsWarper, TopKLogitsWarper, TopPLogitsWarper
  from .generation_stopping_criteria import MaxLengthCriteria, MaxNewTokensCriteria, MaxTimeCriteria, StoppingCriteriaList, validate_stopping_criteria
  from fastNLP.envs.imports import _NEED_IMPORT_TORCH
  from fastNLP.core.log import logger
label_desc: Use image node_id 7 for calling the GenerationMixin obj's underlying member method code with example usage: obj._get_pad_token_id(pad_token_id, eos_token_id) and returns: pad_token_id