Used with sqrt kernel
        :param words:
        :param transformer:
        :return:

def sent2vec(self, words, transformer):
        """
        Used with sqrt kernel
        :param words:
        :param transformer:
        :return:
        """
        sent_vec = np.zeros(transformer.vector_size)
        numw = 0
        for w in words:
            try:
                sent_vec = np.add(sent_vec, transformer.wv[w])
                numw += 1
            except:
                continue
        return sent_vec / np.sqrt(sent_vec.dot(sent_vec))