code: def test_doesnt_change_perplexity_parameter_value(self):
      aff = PerplexityBasedNN(self.x, perplexity=140)
      self.assertEqual(aff.perplexity, 140)
      self.assertEqual(aff.effective_perplexity_, 30)
  
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 TestPerplexityBased obj's underlying member method code with example usage: obj.test_doesnt_change_perplexity_parameter_value() without return types