code: def test_roundness():
      Y, X = -24 + np.indices((48, 48)).astype(float)
      r = roundness((Y**2.0 + X**2.0) < 4**2.0)
      assert r > 0
      r2 = roundness((Y**2.0 + 2 * X**2.0) < 4**2.0)
      assert r2 > 0
      assert r2 < r
  
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 2 for calling a global function with example usage: test_roundness() without return types