code: def test_roberts_diagonal2():
      """Roberts' filter on a diagonal edge should be a diagonal line."""
      image = np.rot90(np.tri(10, 10, 0), 3)
      expected = ~np.rot90(
          np.tri(10, 10, -1).astype(bool)
          | np.tri(10, 10, -2).astype(bool).transpose()
      )
      expected = _mask_filter_result(expected, None)
      result = filters.roberts(image).astype(bool)
      assert_array_almost_equal(result, expected)
  
imports: import numpy
  import pytest
  from numpy.testing import assert_, assert_allclose, assert_array_almost_equal
  from skimage import data, filters
  from skimage._shared.utils import _supported_float_type
  from skimage.filters.edges import _mask_filter_result
label_desc: Use image node_id 4 for calling a global function with example usage: test_roberts_diagonal2() without return types