How to add MXML components to an ActionScript application?
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I'm building an ActionScript 3 project, and have found that writing some components in MXML would simplify things. 

It seems like I'd need to extend the Flex Application class in order to do that. If that is right, how should I do that?

Currently my Main object extends Sprite. Other Sprites are then added to it with `addChild()`, and I'd like Flex components in one of those. Surely there is a way without rewriting my application completely in MXML?