code: def test_io_error(self):
      index = faiss.IndexFlatL2(32)
  
      self.assertTrue("Adds vectors to the index" in index.add.__doc__)
  
imports: import unittest
  import faiss
label_desc: Use image node_id 1 for calling the TestDocumentation obj's underlying member method code with example usage: obj.test_io_error() without return types