Is there a way we can get a notification if a story is added to an Epic

[Matthew Ford]

Is there a way we can get a notification if a story is added to an Epic using scriptrunner listener?  We already have this plugin and I believe there is a way to do it, but I am simply not familiar with the scripting in it.

Can someone help me with:

create a scriptrunner listener for an "issue created" event,

and in the listener
check if there is an "Epic-Story Link" type link, if yes
get the Epic linked to the issue
get the watchers of the Epic
send a mail to these watchers

I was given this at one point:

def issue1 = event.getIssueLink().getSourceObject()
def issue2 = event.getIssueLink().getDestinationObject()

issue1.getIssueType().getName() == "Epic" && issue2.getIssueType().getName() == "Story"

But seems this is not working.  I am getting the following error:

2019-01-14 16:57:40,514 ERROR [runner.AbstractScriptListener]: *************************************************************************************
2019-01-14 16:57:40,514 ERROR [runner.AbstractScriptListener]: Script function failed on event: com.atlassian.jira.event.issue.link.IssueLinkCreatedEvent, script: com.onresolve.scriptrunner.canned.jira.workflow.postfunctions.SendCustomEmail
java.lang.IllegalArgumentException: The issue object was not available in the binding, perhaps called from an event handler with a non-issue event
 at com.onresolve.scriptrunner.canned.jira.workflow.postfunctions.SendCustomEmail.doScript(SendCustomEmail.groovy:517)

Maybe this is not the complete script?