Assign a collection to this alias.
Aliases help determine well known collections, such as 'default'.
If this is null, then [funcService.get] will be called to get the default
[classService] proxy.
This method will return immediately and complete asynchronously.
| this |
a secret service object |
| alias |
the alias to assign the collection to |
| collection |
the collection to assign to the alias |
| cancellable |
optional cancellation object |
| callback |
called when the operation completes |
| user_data |
data to pass to the callback |