code: def test_quantize(self):
      q = haralick.quantize(gray, 7)
      correct = np.array(
          [[0, 0, 2, 2], [0, 0, 2, 2], [0, 4, 4, 4], [4, 4, 6, 6]],
          dtype="i4",
      )
      self.assertTrue((q == correct).all())
  
imports: import unittest
  import centrosome.haralick
  import numpy
label_desc: Use image node_id 1 for calling the TestHaralick obj's underlying member method code with example usage: obj.test_quantize() without return types