code: def test_is_leap_year():
      d = is_leap_year()
      assert isinstance(d, IsLeapYear)
  
      o = d.to_json()
      assert isinstance(o, dict)
      assert o["type"] == "IsLeapYear"
  
      d2 = IsLeapYear.from_json(o)
      assert isinstance(d2, IsLeapYear)
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_is_leap_year() without return types