code: def test_eccentricity():
      D = mh.disk(32, 2)
      ecc = mahotas.features.shape.eccentricity(D)
      assert 0 <= ecc < 0.01
  
      Index = np.indices((33, 33)).astype(float)
      Index -= 15
      X, Y = Index
      ellipse = (X**2 + 2 * Y**2) < 12**2
      assert 0 < mahotas.features.shape.eccentricity(ellipse) < 1
  
file_path: mahotas/mahotas/tests/test_features_shape.py
imports: import mahotas.features.shape
  import numpy
  import mahotas
  from mahotas.features.shape import roundness, eccentricity
label_desc: Use image node_id 1 for calling a global function with example usage: test_eccentricity() without return types