What exactly is the purpose of document_id, doc_id, and ref_doc_id in nodeToMetadata when they all point to the same value?

[shodevacc]

When ingesting documents using an Ingestion pipeline is there a reason why there are three references to node.sourceNode?.nodeId being stored as metadata? What purpose could they serve if they reference the same value?

I'm referring to these lines in the packages/llamaindex/src/storage/vectorStore/utils.ts file:

  metadata["document_id"] = node.sourceNode?.nodeId || "None";
  metadata["doc_id"] = node.sourceNode?.nodeId || "None";
  metadata["ref_doc_id"] = node.sourceNode?.nodeId || "None";

[marcusschiesser]

AFAIK they are there for compatibility reasons with older Python versions. @logan-markewich, correct?