class_docstr: Used for storing and retrieving key value pairs
class_docstr_tok: ["Used","for","storing","and","retrieving","key","value","pairs"]
code: def get_value(self, key_id: int) -> FlaskResponse:
      try:
          kv = (
              db.session.query(models.KeyValue)
              .filter_by(id=key_id)
              .scalar()
          )
          if not kv:
              return Response(status=404, content_type="text/plain")
      except Exception as ex:  # pylint: disable=broad-except
          return json_error_response(utils.error_msg_from_exception(ex))
      return Response(kv.value, status=200, content_type="text/plain")
  
file_path: superset/superset/views/key_value.py
imports: import simplejson
  from flask import request, Response
  from flask_appbuilder import expose
  from flask_appbuilder.hooks import before_request
  from flask_appbuilder.security.decorators import has_access_api
  from werkzeug.exceptions import NotFound
  from superset import db, event_logger, is_feature_enabled
  from superset.models import core
  from superset.superset_typing import FlaskResponse
  from superset.utils import core
  from superset.views.base import BaseSupersetView, deprecated, json_error_response
label_desc: Use image node_id 4 for calling the KV obj's underlying member method code with example usage: obj.get_value(key_id) and returns: Response, Response, json_error_response