class_docstr: multimodal vector retriver:
  text retrieve video or video retrieve text.
class_docstr_tok: ["multimodal","vector","retriver",":","text","retrieve","video","or","video","retrieve","text","."]
code: def make_direct_maps(self):
      faiss.downcast_index(self.db["video"]).make_direct_map()
      faiss.downcast_index(self.db["text"]).make_direct_map()
  
imports: import os
  import numpy
  import pickle
  import time
  from collections import defaultdict
  from ..utils import get_local_rank, print_on_rank0
label_desc: Use image node_id 3 for calling the MMVectorRetriever obj's underlying member method code with example usage: obj.make_direct_maps() without return types