code: def save(self, path: str):
          
          with open(path, 'wb') as out:
              np.save(out, self.lex)
          logger.info("Saved top-k lexicon to \"%s\"", path)
docs: Save lexicon in Numpy array format.  Lexicon will be specific to Sockeye model.
  
          :param path: Path to Numpy array output file.