No Model errors reported when calling Global Controller Method

I managed to crack it

Added this to the Model:
use App\Libraries\L_super;

//===============================================
public function __construct(...$params)
{
$this->l_super = new \App\Libraries\L_super();
}//


//============================================================
public function dbWriteCsv(
string $fCsv,
int $iDevId=0,
string $sensorName='NO NAME???'
)
:int
{
// ...
// ...

$tmp = $this->l_super->addHour2UKTime((string) $row->tstamp, $lBKK=false);
var_dump($tmp);
// /var/www/this-is-a-test.com/app/Models/M_ci4.php:102:int 1548567540