class_docstr: The retriever of REALM outputting the retrieved evidence block and whether the block has answers as well as answer
  positions."
  
      Parameters:
          block_records (`np.ndarray`):
              A numpy array which cantains evidence texts.
          tokenizer ([`RealmTokenizer`]):
              The tokenizer to encode retrieved texts.
code: def save_pretrained(self, save_directory):
      # save block records
      np.save(
          os.path.join(save_directory, _REALM_BLOCK_RECORDS_FILENAME),
          self.block_records,
      )
      # save tokenizer
      self.tokenizer.save_pretrained(save_directory)
  
file_path: H2O/h2o_flexgen/benchmark/third_party/transformers/src/transformers/models/realm/retrieval_realm.py
imports: import os
  from typing import Optional, Union
  import numpy
  from huggingface_hub import hf_hub_download
  from transformers import AutoTokenizer
  from ...utils import logging
label_desc: Use image node_id 4 for calling the RealmRetriever obj's underlying member method code with example usage: obj.save_pretrained(save_directory) without return types