class_docstr: Test retrieval methods for BB2 with RAG.
class_docstr_tok: ["Test","retrieval","methods","for","BB2","with","RAG","."]
code: def test_retrieval_none(self):
      _test_bb2_rag(KnowledgeAccessMethod.NONE, n_docs=1)
  
imports: import copy
  import torch.cuda
  import unittest
  from parlai.core.agents import create_agent
  import parlai.utils.testing
label_desc: Use image node_id 5 for calling the TestBB2Rag obj's underlying member method code with example usage: obj.test_retrieval_none() without return types