class_docstr: A token group (substring) representation used for token clustering.
      
code: def __len__(self):
      return len(self.g)
  
imports: import math
  import re
  import numpy
  from .._serializable import Deserializer, Serializer
  from ..utils import safe_isinstance
  from ..utils.transformers import SENTENCEPIECE_TOKENIZERS, getattr_silent, parse_prefix_suffix_for_tokenizer
  from ._masker import Masker
label_desc: Use image node_id 5 for calling the TokenGroup obj's underlying member method code with example usage: obj.__len__() and returns: len