def get_extra_data(self, data):
        """Get eventual extra data for this placeholder from the
        admin form. This method is called when the Page is
        saved in the admin and passed to the placeholder save
        method."""
        result = {}
        for key in list(data.keys()):
            if key.startswith(self.ctype + '-'):
                new_key = key.replace(self.ctype + '-', '')
                result[new_key] = data[key]
        return result