code: def launch(self, name, index):
      if not index.is_trained:
          index.train(self.xt)
      index.add(self.xb)
      return index.search(self.xq, self.k)
  
file_path: faiss/tests/common_faiss_tests.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import numpy
  import faiss
label_desc: Use image node_id 2 for calling the Randu10k obj's underlying member method code with example usage: obj.launch(name, index) and returns: index