code: def save_to_local(self, callback_etat=print):
          
          callback_etat("Aquisition...", 0, 3)
          d = self.dumps()
          s = json.dumps(d, indent=4, cls=formats.JsonEncoder)
          callback_etat("Chiffrement...", 1, 3)
          s = security.protege_data(s, True)
          callback_etat("Enregistrement...", 2, 3)
          try:
              with open(self.LOCAL_DB_PATH, 'wb') as f:
                  f.write(s)
          except (FileNotFoundError):
              logging.exception(self.__class__.__name__)
              raise StructureError("Chemin de sauvegarde introuvable !")
docs: Saved current in memory base to local file.
          It's a backup, not a convenient way to update datas
  
          :param callback_etat: state callback, taking  str,int,int as args