def vectorize(self, token_list):
        '''
        Tokenize token list.
        
        Args:
            token_list:   The list of tokens..
        
        Returns:
            [vector of token, vector of token, vector of token, ...]
        '''
        vector_list = [self.__collection.tf_idf(token, self.__collection) for token in token_list]
        return vector_list