code: def test_cmc_single_item():
      # Single item case:
      lab1 = lab2 = np.array([0.0, 1.59607713, 0.87755709])
      assert_equal(deltaE_cmc(lab1, lab2), 0)
  
      lab2[0] += np.finfo(float).eps
      assert_equal(deltaE_cmc(lab1, lab2), 0)
  
file_path: scikit-image/skimage/color/tests/test_delta_e.py
imports: import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_almost_equal, assert_equal
  from skimage._shared.testing import fetch
  from skimage._shared.utils import _supported_float_type
  from skimage.color.delta_e import deltaE_cie76, deltaE_ciede94, deltaE_ciede2000, deltaE_cmc
label_desc: Use image node_id 6 for calling a global function with example usage: test_cmc_single_item() without return types