The target architecture byte order. One of :class:`Target.Endian`.

def endian(self):
        """
        The target architecture byte order. One of :class:`Target.Endian`.
        """
        if self._endian is None:
            value = self._DEFAULT_ENDIAN[self.arch]
            if value is None:
                raise NotImplementedError('Could not determine the default byte order of %s architecture.' % self.arch)
            return value
        else:
            return self._endian