class_docstr: Language dependent tokenizer of text document.
class_docstr_tok: ["Language","dependent","tokenizer","of","text","document","."]
code: def to_words(self, sentence):
      words = self._word_tokenizer.tokenize(to_unicode(sentence))
      return tuple(filter(self._is_word, words))
  
imports: from __future__ import absolute_import
  from __future__ import division, print_function, unicode_literals
  import re
  import string
  import zipfile
  import nltk
  from .._compat import to_string, to_unicode, unicode
  from ..utils import normalize_language
label_desc: Use image node_id 6 for calling the Tokenizer obj's underlying member method code with example usage: obj.to_words(sentence) and returns: tuple