"highlight": {
          "knowledge_graph.title.value": [
            "Before 1 January 2018, will <em>South</em> <em>Korea</em> file a World Trade Organization dispute against the United States related to solar panels?"
          ]
        }

def add_highlights_docs(docs):
        """
        "highlight": {
          "knowledge_graph.title.value": [
            "Before 1 January 2018, will <em>South</em> <em>Korea</em> file a World Trade Organization dispute against the United States related to solar panels?"
          ]
        }
        """
        if not isinstance(docs, list):
            docs = [docs]

        for doc in docs:
            if 'matched_sentence' in doc['_source']:
                matched_sentences = doc['_source']['matched_sentence']
                for sentence in matched_sentences:
                    # also add matched sentence to knowledge graph
                    doc['_source']['knowledge_graph']['matched_sentence'] = [{'key': sentence, 'value': sentence}]

                paragraph = SimilarityScoreRerank.get_description(doc)
                if paragraph:
                    high_para = SimilarityScoreRerank.create_highlighted_sentences(matched_sentences, paragraph)
                    if high_para:
                        if 'highlight' not in doc:
                            doc['highlight'] = dict()
                        doc['highlight']['knowledge_graph.description.value'] = [high_para]
        return docs