docs: def _load_w2v(model_file=_f_model, binary=True):
      '''
      load word2vec model
      '''
      if not os.path.exists(model_file):
          print("os.path : ", os.path)
          raise Exception("Model file [%s] does not exist." % model_file)
      return KeyedVectors.load_word2vec_format(
          model_file, binary=binary, unicode_errors='ignore')