Revert "Bug 981729 Fix sdk/lang/functional#throttle tests" for causing bug 981361

This reverts commit 5be6edfa55b250a0416925f158e5b321f99dee05.
Do not unwrap X-rays.
Merge pull request #1429 from Gozala/bug/proper-unwrap@982684

Bug 982684 - Do not unwrap X-rays. r=@Mossop