code: def test_binary_convex_hull():
      #
      # Set the four points of a square to True
      #
      image = numpy.zeros((20, 15), bool)
      image[2, 3] = True
      image[17, 3] = True
      image[2, 12] = True
      image[17, 12] = True
      expected = numpy.zeros((20, 15), bool)
      expected[2:18, 3:13] = True
      result = execute(image, "convex hull")
      assert numpy.all(result == expected)
  
imports: import io
  import centrosome.cpmorphology
  import centrosome.filter
  import numpy
  import pytest
  import scipy.ndimage
  import cellprofiler_core.image
  import cellprofiler_core.measurement
  import cellprofiler.modules.morph
  import cellprofiler_core.object
  import cellprofiler_core.pipeline
  import cellprofiler_core.setting
  import cellprofiler_core.workspace
  import tests.frontend.modules
label_desc: Use image node_id 20 for calling a global function with example usage: test_binary_convex_hull() without return types