code: def test_crop_margin_centered_black_square(self):
      image = np.ones((100, 100, 3), dtype=np.uint8) * 255
      image[45:55, 45:55, :] = 0
      image_processor = self.image_processor
      cropped_image = image_processor.crop_margin(image)
      expected_cropped = image[45:55, 45:55, :]
      self.assertTrue(np.array_equal(expected_cropped, cropped_image))
  
imports: import unittest
  import numpy
  from huggingface_hub import hf_hub_download
  from transformers.testing_utils import require_torch, require_vision
  from transformers.utils import cached_property, is_torch_available, is_vision_available
  from ...test_image_processing_common import ImageProcessingTestMixin, prepare_image_inputs
label_desc: Use image node_id 8 for calling the NougatImageProcessingTest obj's underlying member method code with example usage: obj.test_crop_margin_centered_black_square() without return types