code: def test_add_image_set_by_number(self):
      x = cellprofiler_core.image.ImageSetList()
      y = x.get_image_set(0)
      assert x.count() == 1, "# of elements was %d, should be 1" % (
          x.count()
      )
      assert y.number == 0, (
          "The image set should be #0, was %d" % y.number
      )
      assert (
          "number" in y.keys
      ), "The image set was missing a number key"
      assert (
          y.keys["number"] == 0
      ), "The number key should be zero, was %s" % (
          repr(y.keys["number"])
      )
  
file_path: CellProfiler/tests/core/image/test_image_set_list.py
imports: import numpy
  import cellprofiler_core.image
  import cellprofiler_core.image.abstract_image._callback_image
label_desc: Use image node_id 2 for calling the TestImageSetList obj's underlying member method code with example usage: obj.test_add_image_set_by_number() without return types