public function selectLogin($userName, $password){
        $link= Connect::getConnect();

        $user= new User();
        $userName= $user->setUserName($userName);
        $password= $user->setPassword($password);

        $sql= "SELECT (username, password)
               FROM User
               WHERE username = :username AND password = :password";

        $param= array(':username'=>$user->getUserName(),
                      ':password'=>$user->getPassword());

        try {
            $stmt= $link->prepare($sql);
            $stmt->execute($param);

            // A execução da consulta está retornando false!
            var_dump($stmt->execute($param));

            $query = $stmt->fetchAll(PDO::FETCH_ASSOC);

        } catch (PDOException $e){
            $e->getLine();
            $e->getMessage();
        } catch (Exception $e) {
            $e->getMessage();
        }

    }