RFR: notify: create test utils

[Robin Westberg]

On Wed, 10 Jun 2020 14:48:14 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> please review this patch that moves some static utility functions out from a unit test and into a proper `TestUtils`
> class.
> Testing:
> - [x] `make test` passes on Linux x64
> 
> Thanks,
> Erik

Looks fine!

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Marked as reviewed by rwestberg (Reviewer).

PR: https://git.openjdk.java.net/skara/pull/652