code: def with_single_transaction(resource_name):
      
      transaction_executor_attr_name = "%s_transaction_executor" % resource_name
  
      def class_decorator(cls):
          def _run_proxy(self, *args, **kwargs):
              getattr(self, transaction_executor_attr_name)(
                  self.run,
                  *args,
                  **kwargs
              )
          cls._run_proxy = _run_proxy
          return cls
      return class_decorator
docs: a class decorator for Crontabber Apps.  This decorator will give a class
      a _run_proxy method that passes a databsase connection as a context manager
      into the CronApp's 'run' method.  The run method may then use the
      connection at will knowing that after if 'run' exits normally, the
      connection will automatically be commited.  Any abnormal exit from 'run'
      will result in the connnection being rolledback.
  
      In order for this dectorator to function properly, it must be used in
      conjunction with previous dectorator, "with_transactional_resource" or
      equivalent.  This decorator depends on the mechanims added by that
      decorator.