Small Static Factory Methods

You know how Cocoa classes generally have static methods that serve as factories?

return [NSArray arrayWithObjects:obj1, obj2, nil];

That's a dumb example, especially now that you can do @[obj1, obj2], but why not do the same in AS3? For instance:

return TransactionResponse.FailedResponse();

This would replace something like:

var response:TransactionResponse = new TransactionResponse();
response.success = true;
return response;

Small, slick. Especially handy when you want all of the properties on an object to be read only, i.e. private with getters. BOOM.