def test_credentials_to_from_json(self):
     private_key = datafile('privatekey.pem')
     credentials = PyCryptoSignedJwtAssertionCredentials(
         '*****@*****.**',
         private_key,
         scope='read+write',
         prn='*****@*****.**')
     json = credentials.to_json()
     print json
     restored = Credentials.new_from_json(json)
     print restored.to_json()
     self.assertEqual(credentials.private_key, restored.private_key)
     self.assertEqual(credentials.private_key_password,
                      restored.private_key_password)
     self.assertEqual(credentials.kwargs, restored.kwargs)