I need to write tests for some behavior that needs to check a
constant:

if (MOD_RUBY)
    .... do stuff
else
    .... do something else
end

I can do it by having this sort of thing:

MOD_RUBY = true

and

MOD_RUBY = false

but I don't want to get the ruby warnings.  What's another way for me
to mock this constant?

Thanks,

~ Patrick