It is apparently impossible to use flash builder in conjunction with air native extensions on OSX.
Creating the extension context works without complaint, but calling any of the functions provided
results in "error #3500: The extension context does not have a method named ..."
It cost me a lot of time (and therefore my company's money) to discover that the ANE is actually fine, and can be
invoked outside of flash builder, by an appropriate command line, or by packaging a release executable.
This total package of behavior is very unsatisfactory, and has been known about for at least two years.
Even with the workaround (release packaging, or invoking using a command line) the workflow is
for reference, the most helpful explanation of the workaround is at this URL
http://riawanderer.com/2012/03/27/working-with-air-native-extensions-on-the-mac/ *note the date of this post!*
then search for the panel that follows the text
"Now that simple demo code is ready, let’s run and see what does it do. When you run the app you should see below error indicating that Flex Builder Bug exists :)."