code: def post_load(
      self, data: dict[str, Any], **kwargs: Any
  ) -> dict[str, Any]:
      if data.get("slug"):
          data["slug"] = data["slug"].strip()
          data["slug"] = data["slug"].replace(" ", "-")
          data["slug"] = re.sub(r"[^\w\-]+", "", data["slug"])
      return data
  
imports: import json
  import re
  from typing import Any, Union
  from marshmallow import fields, post_dump, post_load, pre_load, Schema
  from marshmallow.validate import Length, ValidationError
  from superset import security_manager
  from superset.exceptions import SupersetException
  from superset.tags.models import TagType
  from superset.utils import core
label_desc: Use image node_id 1 for calling the BaseDashboardSchema obj's underlying member method code with example usage: obj.post_load(data) and returns: data