code: def __init__(self, previous_secret_key: str) -> None:
      from superset import db  # pylint: disable=import-outside-toplevel
  
      self._db = db
      self._previous_secret_key = previous_secret_key
      self._dialect: Dialect = db.engine.url.get_dialect()
  
imports: import logging
  from abc import ABC, abstractmethod
  from typing import Any, Optional
  from flask import Flask
  from flask_babel import lazy_gettext
  from sqlalchemy import text, TypeDecorator
  from sqlalchemy.engine import Connection, Dialect, Row
  from sqlalchemy_utils import EncryptedType
label_desc: Use image node_id 1 to create a new SecretsMigrator object  with example: obj = SecretsMigrator(previous_secret_key)