'Preprocess attachments for mail_thread.message_post() or mail_mail.create().
:param list attachments: list of attachment tuples in the form ``(name,content)``,
where content is NOT base64 encoded
:param list attachment_ids: a list of attachment ids, not in tomany command form
:param str attach_model: the model of the attachments parent record
:param integer attach_res_id: the id of the attachments parent record'

def _message_preprocess_attachments(self, attachments, attachment_ids, attach_model, attach_res_id):

    return self._message_post_process_attachments(attachments, attachment_ids, {'model': attach_model, 'res_id': attach_res_id})
