code: def test_ellipsoid_const(dtype):
      img = 155 * np.ones((100, 100), dtype=dtype)
      kernel = ellipsoid_kernel((25, 53), 50)
      background = rolling_ball(img, kernel=kernel)
      assert np.allclose(img - background, np.zeros_like(img))
      assert background.dtype == img.dtype
  
file_path: scikit-image/skimage/restoration/tests/test_rolling_ball.py
imports: import numpy
  import pytest
  from skimage import data
  from skimage.restoration._rolling_ball import rolling_ball
  from skimage.restoration._rolling_ball import ellipsoid_kernel
label_desc: Use image node_id 1 for calling a global function with example usage: test_ellipsoid_const(dtype) without return types