code: def is_subword_prefix(self, token: str) -> bool:
      return not token.startswith(RobertaBase.SUBWORD_PREFIX)
  
imports: import abc
  import numpy
  from pathlib import Path
  from typing import Any, Callable, List, Optional, Tuple, Union
  import tensorflow
  import transformers
  from transformers import TFAutoModelForMaskedLM, AutoTokenizer
label_desc: Use image node_id 3 for calling the RobertaBase obj's underlying member method code with example usage: obj.is_subword_prefix(token) and returns: unknown