Hi all, I am playing a little bit around with the GPTKnowledgeGraphIndex to extract triples from unstructured text, however, I was wondering whether it was possible to rely on some user-defined knowledge base rather than performing the task in a completely open fashion. I mean, let's say that you have a knowledge graph with defined entities and a closed set of relation types, can you extract knowledge triples sticking to this prior knowledge base, i.e. involving the original entities and relation types only?