def _verifyConstructorFlag(self, argName, defaultVal):
        """
        Wrap L{verifyConstructorArgument} to provide simpler interface for
        testing  _EDNSMessage constructor flags.

        @param argName: The name of the constructor flag argument
        @param defaultVal: The expected default value of the flag
        """
        assert defaultVal in (True, False)
        verifyConstructorArgument(testCase=self, cls=self.messageFactory,
                                  argName=argName, defaultVal=defaultVal,
                                  altVal=not defaultVal,)

        Wrap L{verifyConstructorArgument} to provide simpler interface for
        testing  _EDNSMessage constructor flags.

        @param argName: The name of the constructor flag argument
        @param defaultVal: The expected default value of the flag
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_dns.py