```coffeescript
class window.OpinionatersEvidence extends Backbone.Model

  opinionaters: ->
    @_opinionaters ?= new Users @get('users')
```

Update opinionaters when model changes
user
```coffeescript
class window.OpinionatersEvidence extends Backbone.Model

  opinionaters: ->
    unless @_opinionaters?
      @_opinionaters = new Users @get('users')
      @on 'change', => @_opinionaters.reset @get('users')
    @_opinionaters
```
assistant