If it's None, don't put it in the cache. If T is None, don't put it in the cache.
if (typeof input != None) putInCache(input)
> if (typeof input != None) putInCache(input)
Exactly, now you've just written exactly the bug I was talking about.
> if (typeof input != None) putInCache(input)
Exactly, now you've just written exactly the bug I was talking about.