Used by Variable/Connection.

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

k = k[1:]
            if k == "_downstream_task_ids":
                
                k = "downstream_task_ids"
            if k == "label":
                
                continue
            elif k == "downstream_task_ids":
                v = set(v)
            elif k == "subdag":
                v = SerializedDAG.deserialize_dag(v)
            elif k in {"retry_delay", "execution_timeout", "sla", "max_retry_delay"}:
                v = cls._deserialize_timedelta(v)
            elif k in encoded_op["template_fields"]:
                pass
            elif k == "resources":
                v = Resources.from_dict(v)
            elif k.endswith("_date"):
                v = cls._deserialize_datetime(v)
            elif k == "_operator_extra_links":
                if cls._load_operator_extra_links:
                    op_predefined_extra_links = cls._deserialize_operator_extra_links(v)
                    
                    op_predefined_extra_links.update(op_extra_links_from_plugin)
                else:
                    op_predefined_extra_links = {}
                v = list(op_predefined_extra_links.values())
                k = "operator_extra_links"
            elif k == "deps":
                v = cls._deserialize_deps(v)