code: def create_access_token(self, request, credentials):
          
          request.realms = self.request_validator.get_realms(
              request.resource_owner_key, request)
          token = {
              'oauth_token': self.token_generator(),
              'oauth_token_secret': self.token_generator(),
              # Backport the authorized scopes indication used in OAuth2
              'oauth_authorized_realms': ' '.join(request.realms)
          }
          token.update(credentials)
          self.request_validator.save_access_token(token, request)
          return urlencode(token.items())
docs: Create and save a new access token.
  
          Similar to OAuth 2, indication of granted scopes will be included as a
          space separated list in ``oauth_authorized_realms``.
  
          :param request: OAuthlib request.
          :type request: oauthlib.common.Request
          :returns: The token as an urlencoded string.