Unary operation: ZeroExtend

        :param new_length: New length after zero-extension
        :return: A new StridedInterval

def zero_extend(self, new_length):
        """
        Unary operation: ZeroExtend

        :param new_length: New length after zero-extension
        :return: A new StridedInterval
        """
        si = self.copy()
        si._bits = new_length

        return si