code: def test_convex3():
      f = np.array(
          [
              [False, False, False, False],
              [False, True, True, False],
              [False, True, False, False],
              [False, False, False, False],
          ],
          dtype=bool,
      )
      assert np.all(fill_convexhull(f) == f)
  
file_path: mahotas/mahotas/tests/test_polygon.py
imports: import numpy
  import mahotas
  import mahotas.polygon
  from mahotas.polygon import fill_polygon, fill_convexhull
  import pytest
label_desc: Use image node_id 3 for calling a global function with example usage: test_convex3() without return types