Native Extension

Hi

I have being working on a Native Extension for a Flex Mobile app and came
across this problem

i want to have a default implementation of the extension written in AS, so
that i can test the app on FB imulator without any errors.but i found that
i could not use any Flex Framework classes in the library. please let me
know how to use them.

what i ideally want to do is supply native extensions for Android and IOS,
any other platform that app runs (Blackberry/Windows Emulator ) should pick
up default AS implementation with some flex controls in it

Please let me know whether this is possible

Thanks
Sumudu