Hi, Mustella (and all the tests) live in the mustella directory of the Flex SDK repo. Be sure to check out the develop branch. https://git-wip-us.apache.org/repos/asf?p=flex-sdk.git;a=tree;f=mustella;hb=refs/heads/develop
It's also mirrored on github: https://github.com/apache/flex-sdk/tree/develop/mustella You can find details on how to set it up and run tests here: https://cwiki.apache.org/FLEX/mustella-overview.html Thanks, Justin