[qmtest] derivation issues?

[eichin at metacarta.com]

>   class DerivedClass(ShellScriptTest):
> 
>     arguments = [TextField(name = "script", computed = 1)]
> 
>     __init__(...):
> 
>       self.script = "find . -name foo"

> However, we blew it in that extension.get_class_arguments is going

Ahh, I was wondering how it was pulling those out...

> to find both arguments.  That's easily fixed by removing duplicates
> in that function, but before we do that, will it work for you?

So it just keeps the "most derived" version?  That makes sense.
Especially for the example that's giving me trouble today:
SubstitutedShellScriptTest does
self.script = self.__PerformSubstitutions(context, self.script)

in Run, before calling MyShellScriptTest.Run, no problems there... but
substituting on self.stdout (etc.) wasn't working -- this would fix
that?