def update_payload(self, fields=None):
        """Wrap submitted data within an extra dict."""
        payload = super(ProvisioningTemplate, self).update_payload(fields)
        if 'template_combinations' in payload:
            payload['template_combinations_attributes'] = payload.pop(
                'template_combinations')
        return {u'provisioning_template': payload}
Wrap submitted data within an extra dict.