src/transformers/models/rag/retrieval_rag.py/RagRetriever/set_ctx_encoder_tokenizer
class RagRetriever:    def set_ctx_encoder_tokenizer(self, ctx_encoder_tokenizer: PreTrainedTokenizer):
        # used in end2end retriever training
        self.ctx_encoder_tokenizer = ctx_encoder_tokenizer
        self.return_tokenized_docs = True