def add_source_text(self, nodes: List[NodeWithScore]) -> List[NodeWithScore]:
        """Combine retrieved nodes/triplets with their source text."""
        og_nodes = self._graph_store.get_llama_nodes(
            [x.node.ref_doc_id for x in nodes if x.node.ref_doc_id is not None]
        )
        node_map = {node.node_id: node for node in og_nodes}

        return self._add_source_text(nodes, node_map)
Combine retrieved nodes/triplets with their source text.
llama-index-core/llama_index/core/indices/property_graph/sub_retrievers/base.py