code: def test_vegalite_output():
      # TODO: somehow test that output is valid HTML/JS?
      spec_with_data = VEGALITE_SPEC.copy()
      spec_with_data["data"] = JSON_DATA
  
      # Test three ways of specifying data
      obj1 = VegaLite(VEGALITE_SPEC, PANDAS_DATA)
      obj2 = VegaLite(VEGALITE_SPEC, JSON_DATA["values"])
      obj3 = VegaLite(spec_with_data)
  
      js1 = obj1._generate_js(id="ABC", sort_keys=True)
      js2 = obj2._generate_js(id="ABC", sort_keys=True)
      js3 = obj3._generate_js(id="ABC", sort_keys=True)
      assert js1 == js2 == js3
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_vegalite_output() without return types