``newargs[i]`` is a string, in this case, it will be something like ``-O``,``-Os``, ``-O2``, or ``-O58``.

Getting a range from a string is just a substring operation, so in the above cases, ``requested_level`` would be ``""``, ``"s"``, ``"2"`` and ``"58"``, and as such, the value comparisons work out fine ...

That said, there is a minor issue with this code which I'll push a fix for now in that it is setting ``requested_level`` to ``'2'`` (a string) and then it skips the code that did the integer conversion.

Fix incoming for that.