Used by Variable/Connection.

https://github.com/apache/airflow/blob/894741e311ffd642e036b80d3b1b5d53c3747cad/airflow/secrets/metastore.py#L32

if var is not None and op.has_dag() and attrname.endswith("_date"):
            
            
            dag_date = getattr(op.dag, attrname, None)
            if var is dag_date or var == dag_date:
                return True
        return super()._is_excluded(var, attrname, op)
    @classmethod
    def _deserialize_deps(cls, deps: list[str]) -> set[BaseTIDep]:
        from airflow import plugins_manager
        plugins_manager.initialize_ti_deps_plugins()
        if plugins_manager.registered_ti_dep_classes is None:
            raise AirflowException("Can not load plugins")
        instances = set()
        for qn in set(deps):
            if (
                not qn.startswith("airflow.ti_deps.deps.")
                and qn not in plugins_manager.registered_ti_dep_classes
            ):
                raise SerializationError(
                    f"Custom dep class {qn} not deserialized, please register it through plugins."
                )
            try:
                instances.add(import_string(qn)())
            except ImportError:
                log.warning("Error importing dep %r", qn, exc_info=True)
        return instances
    @classmethod
    def _deserialize_operator_extra_links(cls, encoded_op_links: list) -> dict[str, BaseOperatorLink]: