def to_bytes(self, inst_data, encoding=None):
        """
        Transform an object into :class:`bytes`.

        :param object inst_data: object to encode
        :param str encoding: character set used to encode the bytes
            returned from the ``dumps`` function.  This defaults to
            :attr:`default_encoding`
        :returns: :class:`tuple` of the selected content
            type and the :class:`bytes` representation of
            `inst_data`

        """
        selected = encoding or self.default_encoding
        content_type = '{0}; charset="{1}"'.format(self.content_type, selected)
        dumped = self._dumps(escape.recursive_unicode(inst_data))
        return content_type, dumped.encode(selected)