code: def write_lock(self, last_update=datetime.datetime.now()):
          
          data = {
              "last_update": last_update.strftime(AppCronLock.DATETIME_FORMAT)
          }
  
          with open(self.lock_file, "w") as writer:
              json.dump(data, writer)
docs: Writes lock file
  
          :param last_update: last update of app