code: def fit(self, sents, **kwargs):
          
          tokens = list(itertools.chain.from_iterable(sents))
          counter = Counter(tokens)
          self.vocab = self.build_vocab(counter, **kwargs)
docs: Builds a vocabulary object based on the tokens in the input.
  
          Args:
              sents: A list of lists of tokens (representing sentences)
  
          Vocab kwargs include:
              max_size
              min_freq
              specials
              unk_init