Collections are ordered sets of objects. Items in the collection can be retrieved by their indexes in the collection (like in an array) or by their ids.
as( Class )
Creates the class factory binding.
Class : function
Specifies which class factory is to be initialized.
using( callbackOrProperty )
Creates callback or property binding.
callbackOrProperty : function | String
When the function is passed, it is used to produce the items. When the string is provided, the property value is used to create the bound collection items.