code: def access_token(self):
          
          access_token = generate_token(length=self.access_token_length[1])
          token_secret = generate_token(self.secret_length)
          client_key = request.oauth.client_key
          self.save_access_token(client_key, access_token,
              request.oauth.resource_owner_key, secret=token_secret)
          return urlencode([(u'oauth_token', access_token),
                            (u'oauth_token_secret', token_secret)])
docs: Create an OAuth access token for an authorized client.
  
          Defaults to /access_token. Invoked by client applications.