class_docstr: check wrt. the scipy implementation 
code: def run_simple_dis_test(self, ref_func, metric_type):
      xq, yb = self.make_example()
      ref_dis = np.array([[ref_func(x, y) for y in yb] for x in xq])
      new_dis = faiss.pairwise_distances(xq, yb, metric_type)
      self.assertTrue(np.allclose(ref_dis, new_dis))
  
imports: import numpy
  import faiss
  import unittest
  from common_faiss_tests import get_dataset_2
  import scipy.spatial.distance
label_desc: Use image node_id 2 for calling the TestExtraDistances obj's underlying member method code with example usage: obj.run_simple_dis_test(ref_func, metric_type) without return types