code: def test_retrieval(self):
      self.rertriever.queries = ["mock query"]
  
      retrieved = self.rertriever.retrieve_and_score(
          torch.LongTensor([[101, 456, 654, 102]])
      )
      self.assertIsNotNone(retrieved)
      self.assertIsInstance(retrieved, tuple)
      self.assertEqual(len(retrieved), 2)
  
      retrieved_docs = retrieved[0]
      self.assertIsInstance(retrieved_docs, list)
      self.assertEqual(len(retrieved_docs), 1)
  
      second_retrieved_doc = retrieved_docs[0][1]
      self.assertIsInstance(second_retrieved_doc, Document)
      self.assertNotEqual(second_retrieved_doc.get_text(), "")
  
file_path: ParlAI/tests/test_searchquery_retrievers.py
imports: import torch
  import unittest
  import parlai.utils.testing
  from parlai.core.params import ParlaiParser
label_desc: Use image node_id 2 for calling the TestSearchQueryFAISSIndexRetriever obj's underlying member method code with example usage: obj.test_retrieval() without return types