Webapp2: Get session value from BaseHandler method

Webapp2: Get session value from BaseHandler method

I'm following webapp2 session documentation:
http://webapp-improved.appspot.com/api/webapp2_extras/sessions.html .
BaseHandler have a class method check_login here i need to check the
session key "login" is exist or not. I tried self.session.get("login") but
it returns error : AttributeError: 'cached_property' object has no
attribute 'get'.
Base.py
import webapp2
from webapp2_extras import sessions
class BaseHandler(webapp2.RequestHandler):
def dispatch(self):
# Get a session store for this request.
self.session_store = sessions.get_store(request=self.request)
try:
# Dispatch the request.
webapp2.RequestHandler.dispatch(self)
finally:
# Save all sessions.
self.session_store.save_sessions(self.response)
@webapp2.cached_property
def session(self):
# Returns a session using the default cookie key.
return self.session_store.get_session()
@classmethod
def check_login(self):
# Check whether session key "login" is exist or not
value = self.session.get("login")
Main.py
from Base import BaseHandler
class MainHandler(BaseHandler):
def __init__(self, request, response):
super(BaseHandler, self).__init__(request, response)
BaseHandler.check_login() # AttributeError: 'cached_property' object
has no attribute 'get'
self.check_login() # AttributeError: 'cached_property' object has no
attribute 'get'