private function getConnection(): PDO
    {
        if ($this->pdo === null) {
            $this->connect($this->dsn);
        }

        return $this->pdo;
    }
private function getConnection(): PDO
    {
        if ($this->pdo === null) {
            $this->connect($this->dsn);
        }

        return $this->pdo;
    }
private function getConnection ( ) : PDO { if ( $ this -> pdo === null ) { $ this -> connect ( $ this -> dsn ) ; } return $ this -> pdo ; }
Return a PDO instance.

@return \PDO
Return a PDO instance .