pub fn condense_question_chain<C: Into<Box<dyn Chain>>>(
        mut self,
        condense_question_chain: C,
    ) -> Self {
        self.condense_question_chain = Some(condense_question_chain.into());
        self
    }
Chain designed to reformulate the question based on the cat history
src/chain/conversational_retrieval_qa/builder.rs