Groovy Script Help For Condition for Group Picker Filed in script Listener

[Kumar]

Hi Team,

I Have a Group Picker Field (Single picker) here i'm trying that when I created a ticket When that particular group value chages to Group "-Y-" in any status only that particular group has to get notification.

Here I'm performing when an issue is updating in the particular group filed  changes to "-Y-" group only that group required the notification. If that field chages to "-X-" or "-Z-" they dont required notification

Here is the steps i have followed 

> I created a custom event named "Notification" and selected the template "issue update" 

> in notification scheme i have selected that group in that partucular custom event.

> in the " Script Listener " a added a custom Listener and added a script 

import com.atlassian.jira.component.ComponentAccessor

def customFieldManager = ComponentAccessor.customFieldManager

def issue = event.issue
def customField = customFieldManager.getCustomFieldObject(10002 as Long)
log.warn("Custom field: " + customField)
def customFieldValue = issue.getCustomFieldValue(customField)
log.warn("Custom field value: " + customFieldValue)

log.warn("Result: " + customFieldValue == "-Y-")
return customFieldValue == "-Y-"

> in events I selected the Issueupdate and Custom Event I created and target project i seletcted the project that i want

>I updated the ticket I got these errors 

2018-12-19 17:17:06,644 WARN [runner.ScriptRunnerImpl]: Custom field:  Group
2018-12-19 17:17:06,644 WARN [runner.ScriptRunnerImpl]: Custom field value: [com.atlassian.crowd.embedded.impl.ImmutableGroup@bd6c997c]
2018-12-19 17:17:06,644 WARN [runner.ScriptRunnerImpl]: false

Can anybody help me with the script

Thanks,

Kumar