code: def test_iter_1(self, dtype):
      image = self.input_image.astype(dtype)
      result = thin(image, 1).astype(bool)
      expected = np.array(
          [
              [0, 0, 0, 0, 0, 0, 0],
              [0, 0, 1, 0, 0, 0, 0],
              [0, 1, 0, 1, 1, 0, 0],
              [0, 0, 1, 1, 1, 0, 0],
              [0, 0, 1, 1, 1, 0, 0],
              [0, 0, 0, 0, 0, 0, 0],
              [0, 0, 0, 0, 0, 0, 0],
          ],
          dtype=bool,
      )
      assert_array_equal(result, expected)
  
imports: import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from scipy.ndimage import correlate
  from skimage import draw
  from skimage._shared.testing import fetch
  from skimage.io import imread
  from skimage.morphology import medial_axis, skeletonize, thin
  from skimage.morphology._skeletonize import G123_LUT, G123P_LUT, _generate_thin_luts
label_desc: Use image node_id 3 for calling the TestThin obj's underlying member method code with example usage: obj.test_iter_1(dtype) without return types