Returns the hash of a list of hashes from sorted repr() of every cookie in jar as
            LWPCookieJar does not change it's hash when cookies change.

def _hash_cookies(self):
        ''' Returns the hash of a list of hashes from sorted repr() of every cookie in jar as
            LWPCookieJar does not change it's hash when cookies change.
        '''
        return hash(frozenset([hash(c) for c in sorted([repr(c) for c in self.session.cookies])]))