[Bug]: Redundant calculation in the title extractor about llama_index HOT 2 CLOSED

async def extract_titles(self, nodes_by_doc_id: Dict) -> Dict:
    titles_by_doc_id = {}
    for key, nodes in nodes_by_doc_id.items():
        if len(nodes) == 1:
            # Directly use the title from the single node
            titles_by_doc_id[key] = await self.llm.apredict(
                PromptTemplate(template=self.node_template),
                context_str=cast(TextNode, nodes[0]).text,
            )
        else:
            title_candidates = await self.get_title_candidates(nodes)
            combined_titles = ", ".join(title_candidates)
            titles_by_doc_id[key] = await self.llm.apredict(
                PromptTemplate(template=self.combine_template),
                context_str=combined_titles,
            )
    return titles_by_doc_id