code: def test_ignore_zeros():
      np.seterr(all="raise")
      np.random.seed(22)
      A = np.zeros((1024, 24), np.uint8)
      A[:24, :24] = np.random.randint(100, 200, size=(24, 24))
      assert rc(A) < 100
      assert otsu(A) < 100
      assert rc(A, ignore_zeros=1) > 100
      assert otsu(A, ignore_zeros=1) > 100
  
file_path: mahotas/mahotas/tests/test_thresholding.py
imports: import numpy
  from mahotas.thresholding import otsu, rc, bernsen, gbernsen
  from mahotas.histogram import fullhistogram
  import pytest
label_desc: Use image node_id 5 for calling a global function with example usage: test_ignore_zeros() without return types