anyone knows the flex metadata mechanism

When I use flexunit for tests, I confused about the metadata like [Test], [Test(async, ui)], anyone knows how 开发者_Go百科does the metadata parsed by the flex? how to define my own metadata

You should use [Test(async)] when you're waiting for an asynchronous event in a test method. Async tells the framework not to declare the method a success just yet, and that there is something else (an event) we need to account for to make that decision.