error on shaCompose

[perie]

Attempted to call function "shaCompose" from namespace "BitBag\MercanetBnpParibasPlugin\Legacy"

public function shaCompose(array $parameters)
    {
        // compose SHA string
        $shaString = '';
        foreach ($parameters as $key => $value) {
            if ($key != 'keyVersion') {
                if (is_array($value)) {
                    shaCompose($value);
                } else {
                    $shaString .= $value;
                }
            }
        }
        $shaString = str_replace("[", "", $shaString);
        $shaString = str_replace("]", "", $shaString);
        $shaString = str_replace("\",\"", "", $shaString);
        $shaString = str_replace("\"", "", $shaString);
        return $shaString;
    }

missing the $this-> before the shaCompose call;

This issue does not allow multiple payment with the instalment data.