code: def test_3d_motion():
      # Generate synthetic data
      rng = np.random.default_rng(0)
      image0 = rng.normal(size=(100, 100, 100))
      gt_flow, image1 = _sin_flow_gen(image0)
      # Estimate the flow
      flow = optical_flow_tvl1(image0, image1, attachment=10)
      # Assert that the average absolute error is less then half a pixel
      assert abs(flow - gt_flow).mean() < 0.5
  
file_path: scikit-image/skimage/registration/tests/test_tvl1.py
imports: import numpy
  import pytest
  from skimage._shared.utils import _supported_float_type
  from skimage.registration import optical_flow_tvl1
  from skimage.transform import warp
label_desc: Use image node_id 3 for calling a global function with example usage: test_3d_motion() without return types