Add a Undo for replaceing files

I've been holding this one back for a while now as I thought this to be an issue that only stemmed from my stupidity.

Please for the love of everything that is sacred (Gol if you have to or something) add an Undo for the replacing action of dropping a sample onto another one!

It's such a pain in the arse when I accidentally press the sample playback button on the sampler to fast and accidentally start dragging the sample and then let go instantly and replace my kick with a 4 bar synth loop I stemmed out or something.

Or just miss the clip of what I intended to drop stuff onto when trying out stuff from my own kicks or something.

Or even just thinking "Nah, doesn't work or sound good".

Its such a pain in the ass to go and look for what I just replaced back in my library of sounds.
It stops me dead in my tracks.

Now I get this occasionally, but I just had an influx of this happening because I recently switched over to a trackball again, and I still need to get used to using one.
But seriously, it doesn't make sense unless there is a really good software reason why that isn't already implemented.
I've been using FL for a few years now, and this is still something that still happens sometimes, and it always takes at least 2 minutes to fix everytime it happens.

Sorry If I gave up on my manners for this post, but this is really aggravating.