Why does this not work: issueFunction in expression("", "creator = reporter")

[Helle Overbeck]

According to Scriptrunner guide this is a valid expression

issueFunction in expression("", "creator != reporter")

 But I would like to find all issues where creator and reporter are the same. I tried

issueFunction in expression("", "creator = reporter")

But get this error

Token ("=" at 1:10: "=" ) is not allowed

Is there any other way to find issues where two fields are identical? 

[Mihamina · Accepted solution]

Would you try "==" an see if it works ?

[Helle Overbeck]

It works :-)

Thank you very much!

[Mihamina]

Please upvote :-p