protected function setPropertySources()
    {
        $this->propertySources = array();
        $this->propertySources['invoiceSource'] = $this->invoiceSource;
        if (array_key_exists(Source::CreditNote, $this->shopCapabilities->getSupportedInvoiceSourceTypes())) {
            $this->propertySources['originalInvoiceSource'] = $this->invoiceSource->getOrder();
        }
        $this->propertySources['source'] = $this->invoiceSource->getSource();
        if (array_key_exists(Source::CreditNote, $this->shopCapabilities->getSupportedInvoiceSourceTypes())) {
            if ($this->invoiceSource->getType() === Source::CreditNote) {
                $this->propertySources['refund'] = $this->invoiceSource->getSource();
            }
            $this->propertySources['order'] = $this->invoiceSource->getOrder()->getSource();
            if ($this->invoiceSource->getType() === Source::CreditNote) {
                $this->propertySources['refundedInvoiceSource'] = $this->invoiceSource->getOrder();
                $this->propertySources['refundedOrder'] = $this->invoiceSource->getOrder()->getSource();
            }
        }
    }