def METHOD_NAME(self, a_str, isNDR64):
    try:
        hexData = getattr(self, 'hexData64' if isNDR64 else 'hexData')
        # Regression check
        self.assertEqual(hexl(a_str), hexData)
    except AttributeError:
        # Show result, to aid adding regression check
        print(self.__class__.__name__, isNDR64, hexl(a_str))