Once I have already created a Knowledge Graph Index using the "from_documents" method, how can I just load the index from the existing Neo4j knowledge graph that I've created?

Does anyone know how to pip install from a specific branch of llama index? I've tried pip install git+https://github.com/rohans30/llama_index.git@prevchunks but when I checked my locally installed files I didn't see my changes reflected

I'm trying to use RankLLM by following this guide: https://docs.llamaindex.ai/en/stable/examples/node_postprocessor/rankLLM/ , but even after pip installing all the modules I keep getting the error that there is No module named 'llama_index.postprocessor.rankLLM_rerank', and I check the directory of the important and in fact the llama_index.postprocessor module does not have a rankLLM submodule