code: def test_expected_output(self):
      dummy_image = self.image_processor_tester.prepare_dummy_image()
      image_processor = self.image_processor
      inputs = image_processor(dummy_image, return_tensors="pt")
      self.assertTrue(
          torch.allclose(
              inputs["pixel_values"].mean(),
              torch.tensor(0.4906),
              atol=1e-3,
              rtol=1e-3,
          )
      )
  
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 6 for calling the NougatImageProcessingTest obj's underlying member method code with example usage: obj.test_expected_output() without return types