code: def test_constants(self):
      for c in [None, True, False]:
          self.assertTrue(json.loads(json.dumps(c)) is c)
          self.assertTrue(json.loads(json.dumps([c]))[0] is c)
          self.assertTrue(json.loads(json.dumps({"a": c}))["a"] is c)
  
imports: from unittest import TestCase
  from simplejson.compat import StringIO, long_type, b, binary_type, text_type, PY3
  import simplejson
label_desc: Use image node_id 2 for calling the TestDump obj's underlying member method code with example usage: obj.test_constants() without return types