fkooman\OAuth\Client\RefreshToken::getRefreshToken PHP Method

    public function getRefreshToken()
    {
        return $this->refreshToken;
    }

 public function deleteRefreshToken(RefreshToken $refreshToken)
 {
     $stmt = $this->db->prepare("DELETE FROM refresh_tokens WHERE client_config_id = :client_config_id AND user_id = :user_id AND refresh_token = :refresh_token");
     $stmt->bindValue(":client_config_id", $refreshToken->getClientConfigId(), PDO::PARAM_STR);
     $stmt->bindValue(":user_id", $refreshToken->getUserId(), PDO::PARAM_STR);
     $stmt->bindValue(":refresh_token", $refreshToken->getRefreshToken(), PDO::PARAM_STR);
     $stmt->execute();
     return 1 === $stmt->rowCount();
 }