code: def test_index_type(self):
      import faiss
  
      knn_func = FaissKNN(
          reset_after=False, index_init_fn=faiss.IndexFlatIP
      )
      AC = accuracy_calculator.AccuracyCalculator(knn_func=knn_func)
      embeddings = torch.randn(1000, 32)
      labels = torch.randint(0, 10, size=(1000,))
      AC.get_accuracy(embeddings, labels)
      self.assertTrue(isinstance(AC.knn_func.index, faiss.IndexFlatIP))
  
imports: import itertools
  import logging
  import unittest
  import numpy
  import torch
  from pytorch_metric_learning.distances import LpDistance
  from pytorch_metric_learning.utils import accuracy_calculator
  from pytorch_metric_learning.utils.common_functions import LOGGER
  from pytorch_metric_learning.utils.inference import CustomKNN, FaissKMeans, FaissKNN
  from ..None import TEST_DEVICE
label_desc: Use image node_id 2 for calling the TestCalculateAccuraciesFaissKNN obj's underlying member method code with example usage: obj.test_index_type() without return types