[Twisted-Python] Appropriate exception for AMP types receiving garbage?

Hi, I'm writing a custom AMP type. I noticed that when writing the unit test for garbage input, I didn't really know what exception to check for. I couldn't find any place where this was formally defined, so I checked for implementation behavior. Boolean explicitly raises TypeError. Integer raises ValueError, but that appears to only be an implementation detail of int. It could also be that it doesn't matter at all, but it does seem a little strange that Integer and Boolean raise different exceptions when fed garbage... -- cheers lvh