code: def test_that_regular_matrix_sums_to_one(self):
      for method_name, cls in AFFINITY_CLASSES:
          aff: affinity.Affinities = cls(self.iris)
          self.assertAlmostEqual(np.sum(aff.P), 1, msg=method_name)
  
imports: import logging
  import unittest
  from functools import partial
  import numpy
  from scipy.spatial.distance import squareform, pdist
  from sklearn import datasets
  from sklearn.model_selection import train_test_split
  from openTSNE import affinity, nearest_neighbors
label_desc: Use image node_id 2 for calling the TestAffinityMatrixCorrectness obj's underlying member method code with example usage: obj.test_that_regular_matrix_sums_to_one() without return types