code: def test_relate_zeros_with_step_parent(self):
      # https://github.com/CellProfiler/CellProfiler/issues/2441
      parents = numpy.zeros((10, 10), dtype=numpy.uint8)
  
      children = numpy.zeros_like(parents)
  
      step_parents = numpy.zeros_like(parents)
  
      step_parents_object = cellprofiler_core.object.Objects()
  
      step_parents_object.segmented = step_parents
  
      workspace, module = self.make_workspace(parents, children)
  
      workspace.measurements.add_measurement(
          "Step", FF_PARENT % PARENT_OBJECTS, []
      )
  
      module.step_parent_names[0].step_parent_name.value = "Step"
  
      workspace.object_set.add_objects(step_parents_object, "Step")
  
      module.wants_step_parent_distances.value = True
  
      module.find_parent_child_distances.value = (
          cellprofiler.modules.relateobjects.D_MINIMUM
      )
  
      module.run(workspace)
  
      expected = []
  
      actual = workspace.measurements.get_current_measurement(
          CHILD_OBJECTS,
          cellprofiler.modules.relateobjects.FF_MINIMUM % "Step",
      )
      numpy.testing.assert_array_equal(actual, expected)
  
imports: import numpy
  import unittest
  import cellprofiler_core.image
  import cellprofiler_core.measurement
  import cellprofiler_core.module
  from cellprofiler_core.constants.measurement import C_PARENT, GROUP_NUMBER, GROUP_INDEX, COLTYPE_FLOAT, COLTYPE_INTEGER, M_LOCATION_CENTER_X, M_LOCATION_CENTER_Y, FF_PARENT
  import cellprofiler.modules.relateobjects
  import cellprofiler_core.object
  import cellprofiler_core.pipeline
  import cellprofiler_core.preferences
  import cellprofiler_core.workspace
label_desc: Use image node_id 15 for calling the TestRelateObjects obj's underlying member method code with example usage: obj.test_relate_zeros_with_step_parent() without return types