You want to render a list of `UsersToSubjects` models (hardcoded for now `user=3` in `urls.js`). So the idea with this list is that it:
1. uses the `channels` param to receive items on it, and renders each item in a list (`<ul> <li> item1 </li> <li> item2 </li> ... </ul>`), but to do that, it needs to know the type of the item to render, so you need ...
2. to provide `item` param, which tells the list what type of widget it needs to load for each item it receives on `/items` channel
3. but to instantiate each item widget (here a `userstosubjects` widget), you want that widget to listen on `/subjects` and on `/userstosubjects/the_item's_id`, so you need to add these channels in `item_channels`, so the list may pass these channels along to each `<li> item widget</li>`, when instantiating it. So the `item_channels` should look like this:

```coffeescript
item_channels:
    '/items': userstosubjects
    '/subjects': subjects
```

And if you want a custom template for your list, add the `template_name` to `list_params` as @topliceanu suggested.