private void checkTriggerVarList() throws ScraperConfigurationException {
        boolean first = true;
        for(TriggerElement triggerElement:this.triggerElementList){
            if(!first && triggerElement.getConcatType()==null){
                throw new ScraperConfigurationException("A concat for the second and following trigger must be given!");
            }
            first = false;
        }
    }
checks the trigger list for correct syntax
@throws ScraperConfigurationException if syntax isn't correct an exception is thrown
plc4j/tools/scraper/src/main/java/org/apache/plc4x/java/scraper/triggeredscraper/triggerhandler/TriggerConfiguration.java