class_docstr: Class that holds a vocabulary for the dataset.
class_docstr_tok: ["Class","that","holds","a","vocabulary","for","the","dataset","."]
code: def word_to_id(self, word):
      if word in self._word_to_id:
          return self._word_to_id[word]
      return self.unk
  
imports: import random
  import numpy
  from textattack.shared.utils import LazyLoader
label_desc: Use image node_id 6 for calling the Vocabulary obj's underlying member method code with example usage: obj.word_to_id(word) and returns: self, self