Knowledge Graph Rag (Community) - Steps Missing

I am trying to run the Community Graph RAG example as mentioned here. But it looks like there are some steps missing between 6 and 7. When I am doing the python server.py as mentioned in Step 7 I am getting the following error

Traceback (most recent call last):
  File "D:\KnowledgeGrpahRAG\GenerativeAIExamples\community\knowledge_graph_rag\backend\server.py", line 18, in <module>
    from routers import ui_backend,chat,evaluation,visualization
  File "D:\KnowledgeGrpahRAG\GenerativeAIExamples\community\knowledge_graph_rag\backend\routers\chat.py", line 42, in <module>
    KG_GRAPHML_PATH = os.path.join(DATA_DIR, "knowledge_graph.graphml")
  File "C:\Users\avish\AppData\Local\Programs\Python\Python310\lib\ntpath.py", line 104, in join
    path = os.fspath(path)
TypeError: expected str, bytes or os.PathLike object, not NoneType

It is looking for knowledge_graph.graphml which possibly is created through some other scripts but not mentioned there. Possibly it will need pre-execution of lc_graph.py under utils folder. Any help to figure out what to do would be appreciated.

阅读 Community Graph RAG 中围绕步骤 6 和 7 的说明，然后检查 community/knowledge_graph_rag/backend/server.py 以及提到的 utils/lc_graph.py。记录 knowledge_graph.graphml 所缺少的前置条件或生成步骤，以便用户可以按照示例操作并在没有报告的错误的情况下启动 server.py。