ActionScript 3.0 :: Custom Class Which Uses Multiple Assets From Flash Library - How To Do It

I've seen that it's very simple to create a document class (a class associated to the main timeline itself), or an instance of a class which is linked to a single asset (e.g. a movie clip).But what if I need to implement a class (let's call it Main) which uses multiple assets from the Flash library? The only way I know to do this is by instantiating any asset with its linked class, and passing them all to the Main constructor like this:

ActionScript Code:
var asset1:Asset1 = new Asset1(...);
var asset2:Asset2 = new Asset2(...);
var asset3:Asset3 = new Asset3(...);

[code].....

This is kind of a tedious process, especially when the composition hierarchy is long and you have to pass them all as arguments through many nested classes.For instance, I needed to link a preload sprite (the typical circle in gradient color which is constantly rotating until the load is complete) from the library to any thumbnail class of a gallery, which in turn is part of another class, which in turn is part of the main class. So I needed to pass this preload clip as an argument throughout the nested classes.