Flex Actionscript Project with SWC component: curious about how it runs?

Hey guys, I got this Actionscript Project that i downloaded. It comes with an SWC file which i’ve added in the library path and it has these packages and class files. When I run the project, it does what it’s supposed to do, but im not sure how it’s actually running because i see classes and class definitions but no instantiation of any classes?

Like, there’s an addChild inside the classes, but whats actually calling these functions? It’s all function declarations and definitions and no actual calls?

Any ideas?