"""
        Test that the dag file processor does not try to insert already existing item into the database
        """
        session = settings.Session()
        
        
        test_start_date = timezone.utcnow() - datetime.timedelta(days=2)
        with dag_maker(
            dag_id="test_sla_miss",
            default_args={"start_date": test_start_date, "sla": datetime.timedelta(days=1)},
        ) as dag:
            task = EmptyOperator(task_id="dummy")
        dag_maker.create_dagrun(execution_date=test_start_date, state=State.SUCCESS)
        
        ti = TaskInstance(task=task, execution_date=test_start_date, state="success")
        session.merge(ti)
        session.flush()
        dag_file_processor = DagFileProcessor(
            dag_ids=[], dag_directory=TEST_DAGS_FOLDER, log=mock.MagicMock()
        )
        dag_file_processor.manage_slas(dag=dag, session=session)
        sla_miss_count = (
            session.query(SlaMiss)
            .filter(
                SlaMiss.dag_id == dag.dag_id,
                SlaMiss.task_id == task.task_id,
            )
            .count()