//  [python]
def evaluate_batch(self, batch_hyps, batch_refs, idf_hyps=None, idf_ref=None):
        """
        :param batch_hyps: hypothesis list of string sentences
        :param batch_refs: reference list of string sentences
        :return: dictionnary of scores
        """
        ###############################################
        ## Extract Embeddings From Pretrained Models ##
        ###############################################
        if isinstance(batch_hyps, str):
            batch_hyps = [batch_hyps]
        if isinstance(batch_refs, str):
            batch_refs = [batch_refs]
        nb_sentences = len(batch_refs)
        depth_scores = []
        assert len(batch_hyps) == len(batch_refs)

        model = self.model.to(self.device)

        with torch.no_grad():
            ###############################################
            ## Extract Embeddings From Pretrained Models ##
            ###############################################
            batch_refs = self.tokenizer(batch_refs, return_tensors='pt', padding=True, truncation=True).to(self.device)
            batch_refs_embeddings_ = model(**batch_refs)[-1]

            batch_hyps = self.tokenizer(batch_hyps, return_tensors='pt', padding=True, truncation=True).to(self.device)
            batch_hyps_embeddings_ = model(**batch_hyps)[-1]

            batch_refs_embeddings = [batch_refs_embeddings_[i] for i in [self.layers_to_consider]]
            batch_hyps_embeddings = [batch_hyps_embeddings_[i] for i in [self.layers_to_consider]]

            batch_refs_embeddings = torch.cat([i.unsqueeze(0) for i in batch_refs_embeddings])
            batch_refs_embeddings.div_(torch.norm(batch_refs_embeddings, dim=-1).unsqueeze(-1))
            batch_hyps_embeddings = torch.cat([i.unsqueeze(0) for i in batch_hyps_embeddings])
            batch_hyps_embeddings.div_(torch.norm(batch_hyps_embeddings, dim=-1).unsqueeze(-1))

            ref_tokens_id = batch_refs['input_ids'].cpu().tolist()
            hyp_tokens_id = batch_hyps['input_ids'].cpu().tolist()

            ######################################
            ## Unbatched Depth Score Prediction ##
            ######################################
            for index_sentence in tqdm(range(nb_sentences), 'Depth Score Progress'):
                ref_tokens = [i for i in self.tokenizer.convert_ids_to_tokens(ref_tokens_id[index_sentence],
                                                                              skip_special_tokens=False) if
                              i != self.tokenizer.pad_token]
                hyp_tokens = [i for i in self.tokenizer.convert_ids_to_tokens(hyp_tokens_id[index_sentence],
                                                                              skip_special_tokens=False) if
                              i != self.tokenizer.pad_token]

                ref_ids = [k for k, w in enumerate(ref_tokens) if True]
                hyp_ids = [k for k, w in enumerate(hyp_tokens) if True]

                ref_embedding_i = batch_refs_embeddings[:, index_sentence, ref_ids, :]
                hyp_embedding_i = batch_hyps_embeddings[:, index_sentence, hyp_ids, :]
                measures_locations_ref = ref_embedding_i.permute(1, 0, 2).cpu().numpy().tolist()
                measures_locations_ref = [np.array(i) for i in measures_locations_ref]
                measures_locations_hyps = hyp_embedding_i.permute(1, 0, 2).cpu().numpy().tolist()
                measures_locations_hyps = [np.array(i) for i in measures_locations_hyps]

                dict_score = self.depth_score(measures_locations_ref, measures_locations_hyps)
                depth_scores.append(dict_score)
        depth_scores_dic = {}
        for k in dict_score.keys():
            depth_scores_dic[k] = []
            for score in depth_scores:
                depth_scores_dic[k].append(score[k])
        return depth_scores_dic