code: def test_H6(self):
      h = haralick.Haralick(gray, labels, 0, 1, nlevels=4)
      self.assertAlmostEqual(h.H6()[0], 4.5833, 4)
  
imports: import unittest
  import centrosome.haralick
  import numpy
label_desc: Use image node_id 10 for calling the TestHaralick obj's underlying member method code with example usage: obj.test_H6() without return types