code: def test_unify_nothing():
      labels = numpy.zeros((10, 20), int)
      for um in (
          cellprofiler.modules.splitormergeobjects.UM_DISCONNECTED,
          cellprofiler.modules.splitormergeobjects.UM_CONVEX_HULL,
      ):
          labels_out, workspace = rruunn(
              labels,
              cellprofiler.modules.splitormergeobjects.OPTION_MERGE,
              merge_option=cellprofiler.modules.splitormergeobjects.UNIFY_PARENT,
              unify_method=cellprofiler.modules.splitormergeobjects.UM_CONVEX_HULL,
              parent_object="Parent_object",
              parents_of=numpy.zeros(0, int),
          )
          assert numpy.all(labels_out == 0)
  
imports: import numpy
  import six.moves
  import cellprofiler_core.image
  import cellprofiler_core.measurement
  import cellprofiler_core.measurement
  from cellprofiler_core.constants.measurement import M_LOCATION_CENTER_X, M_LOCATION_CENTER_Y, FF_COUNT, FF_PARENT, COLTYPE_FLOAT, M_NUMBER_OBJECT_NUMBER, COLTYPE_INTEGER, FF_CHILDREN_COUNT
  import cellprofiler.modules.splitormergeobjects
  import cellprofiler_core.object
  import cellprofiler_core.pipeline
  import cellprofiler_core.workspace
  import tests.frontend.modules
label_desc: Use image node_id 17 for calling a global function with example usage: test_unify_nothing() without return types