class_docstr: fairseq base dataclass that supported fetching attributes and metas
code: def _get_default(self, attribute_name: str) -> Any:
      if hasattr(self, attribute_name):
          if str(getattr(self, attribute_name)).startswith("${"):
              return str(getattr(self, attribute_name))
          elif str(
              self.__dataclass_fields__[attribute_name].default
          ).startswith("${"):
              return str(
                  self.__dataclass_fields__[attribute_name].default
              )
          elif (
              getattr(self, attribute_name)
              != self.__dataclass_fields__[attribute_name].default
          ):
              return getattr(self, attribute_name)
  
      f = self.__dataclass_fields__[attribute_name]
      if not isinstance(f.default_factory, _MISSING_TYPE):
          return f.default_factory()
      return f.default
  
imports: import os
  import sys
  from dataclasses import _MISSING_TYPE, dataclass, field
  from typing import Any, List, Optional
  import torch
  from omegaconf import II, MISSING
  from fairseq.dataclass.constants import DATASET_IMPL_CHOICES, DDP_BACKEND_CHOICES, DDP_COMM_HOOK_CHOICES, GENERATION_CONSTRAINTS_CHOICES, GENERATION_DECODING_FORMAT_CHOICES, LOG_FORMAT_CHOICES, PIPELINE_CHECKPOINT_CHOICES, PRINT_ALIGNMENT_CHOICES, ZERO_SHARDING_CHOICES
label_desc: Use image node_id 5 for calling the FairseqDataclass obj's underlying member method code with example usage: obj._get_default(attribute_name) and returns: f, f, str, str, getattr