This is a mocking tool used by a few of our libraries for testing, that tooling should be shared.
<rdar://problem/68307522>
Created attachment 407933 [details] Patch
Created attachment 407993 [details] Patch
Created attachment 408027 [details] Patch for landing
Committed r266640: <https://trac.webkit.org/changeset/266640> All reviewed patches have been landed. Closing bug and clearing flags on attachment 408027 [details].