public function getTriggerCreditNoteEventOptions()
    {
        $result = array(
            PluginConfig::TriggerCreditNoteEvent_None => $this->t('option_triggerCreditNoteEvent_0'),
        );

        if (in_array(Source::CreditNote, $this->getSupportedInvoiceSourceTypes())) {
            $result[PluginConfig::TriggerCreditNoteEvent_Create] = $this->t('option_triggerCreditNoteEvent_1');
        }

        return $result;
    }