class_docstr: This masks out tokens according to the given tokenizer.
  
  The masked variables are
  
  output_type : "string" (default) or "token_ids"
docstr: The names of the features for each mask position for the given input string.
          
code: def feature_names(self, s):
      """The names of the features for each mask position for the given input string."""
      self._update_s_cache(s)
      return [[v.strip() for v in self._segments_s]]
  
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 10 for calling the Text obj's underlying member method code with example usage: obj.feature_names(s) and returns: list