Preconstrain the data in the flag page.

        :param magic_content:   The content of the magic page as a bytestring.

def preconstrain_flag_page(self, magic_content):
        """
        Preconstrain the data in the flag page.

        :param magic_content:   The content of the magic page as a bytestring.
        """
        for m, v in zip(magic_content, self.state.cgc.flag_bytes):
            self.preconstrain(m, v)