Used in https://github.com/mhenc/airflow/blob/master/airflow/dag_processing/manager.py#L613

should be straighforward
"""
    A table to store DAG warnings.
    DAG warnings are problems that don't rise to the level of failing the DAG parse
    but which users should nonetheless be warned about.  These warnings are recorded
    when parsing DAG and displayed on the Webserver in a flash message.
    """
    dag_id = Column(StringID(), primary_key=True)
    warning_type = Column(String(50), primary_key=True)
    message = Column(Text, nullable=False)
    timestamp = Column(UtcDateTime, nullable=False, default=timezone.utcnow)
    __tablename__ = "dag_warning"
    __table_args__ = (
        ForeignKeyConstraint(
            ("dag_id",),
            ["dag.dag_id"],
            name="dcw_dag_id_fkey",
            ondelete="CASCADE",
        ),
    )
    def __init__(self, dag_id: str, error_type: str, message: str, **kwargs):
        super().__init__(**kwargs)
        self.dag_id = dag_id
        self.warning_type = DagWarningType(error_type).value  
        self.message = message
    def __eq__(self, other) -> bool: