Usage of ref_doc_id of Node parsed

[Joshua-Yu]

Hi there,

I was trying to figure out which node belongs to which document so I used ref_doc_id of node, but it didn't seem to refer to the document. Below is my code:

from llama_index.core.node_parser import MarkdownElementNodeParser

node_parser = MarkdownElementNodeParser(llm=llm, num_workers=8)
nodes = node_parser.get_nodes_from_documents(documents)

base_nodes, objects = node_parser.get_nodes_and_objects(nodes)

for node in base_nodes:
    print(f"ref_doc:{node.ref_doc_id}")
    ... ... 

Any suggestion?

Cheers