/**
  * Get a session from an access token.
  *
  * @param \League\OAuth2\Server\Entity\AccessTokenEntity $accessToken The access token
  *
  * @return \League\OAuth2\Server\Entity\SessionEntity
  */
 public function getByAccessToken(AccessTokenEntity $accessToken)
 {
     $result = Config::get('couch.client')->useDatabase('oauth_sessions')->getDoc($accessToken->getSessionId());
     if (is_null($result)) {
         return;
     }
     config('session', $result);
     return (new SessionEntity($this->getServer()))->setId($result->_id)->setOwner($result->owner_type, $result->owner_id);
 }