$_SESSION['customer']['items'] = getItems() //returns an array
$_SESSION['article'][$Id]['name'] = utf8_decode[$received[1]];

class CustomerPopo
{

    private $_id;

    private $_salutation;

    private $_name;

    private $_surename;

        public function getId()
    {
        return $this->_id;
    }

    public function setId($value)
    {
        $this->_id = $value;
    }

    public function getSalutation()
    {
        return $this->_salutation;
    }

    public function setSalutation($value)
    {
        $this->_salutation = $value;
    }

    public function getName()
    {
        return $this->_name;
    }

    public function setName($value)
    {
        $this->_name = $value;
    }

    public function getSurename()
    {
        return $this->_surename;
    }

    public function setSurename($value)
    {
        $this->_surename = $value;
    }

    function CustomerPopo() {

    }
}

class SessionManager
{

    private static function getValue($valueName)
    {
        $value = SessionManager::getValueFromSession($valueName);
        if (is_null($value)) {
             //Handle stuff and do further checks
        }
        return $value;
    }

    private static function getValueFromSession($valueName)
    {
        $value = null;
        if (isset($_SESSION[$valueName])) {
            $value = $_SESSION[$valueName];
        }
        return $value;
    }

    private static function setValue($valueName, $value)
    {
        $_SESSION[$valueName] = $value;
    }

    private static function clearValue($valueName)
    {
        if (isset($_SESSION[$valueName])) {
            unset($_SESSION[$valueName]);
        }
    }

    public static function getCustomer()
    {
        $customer = '';
        try {
            $customer = SessionManager::getValue('customer');
        } catch (Exception $e) {
            $customer = '';
        }
        return $customer;
    }

    public static function setCustomer($customer)
    {
        SessionManager::setValue('customer', $customer);
    }
}