code: def test_cooccurrence(self):
      P, levels = haralick.cooccurrence(gray4, labels, 0, 1)
      correct = np.array(
          [[[2, 2, 1, 0], [0, 2, 0, 0], [0, 0, 3, 1], [0, 0, 0, 1]]],
          float,
      )
      correct = correct / np.sum(correct)
      self.assertEqual(levels, 4)
      self.assertTrue((P == correct).all())
  
imports: import unittest
  import centrosome.haralick
  import numpy
label_desc: Use image node_id 4 for calling the TestHaralick obj's underlying member method code with example usage: obj.test_cooccurrence() without return types