Add a property check when iterating over alert groups in example
Add a property check when iterating over alert groups in example

lowtalker/splunk-sdk-javascript,splunk/splunk-sdk-javascript,adamryman/splunk-sdk-javascript,splunk/splunk-sdk-javascript,lowtalker/splunk-sdk-javascript,splunk/splunk-sdk-javascript,adamryman/splunk-sdk-javascript