I'm using Rails 4 **[collection\_check\_boxes](http://apidock.com/rails/v4.0.2/ActionView/Helpers/FormOptionsHelper/collection_check_boxes)** in my forms. Filling out the form, I check some of the checkboxes. I've noticed that when the form refreshes after validation error, the checkboxes that were checked persists. Is this a feature of the tag? I couldn't find this information in the docs. 

Checkbox form field code: 

```
<div class="field">
  <%= f.label "Area of Interest" %><br />
  <%= f.collection_check_boxes :interest_ids, Interest.all, :id, :name do |b| %>
    <div class="collection-check-box">
      <%= b.check_box %>
      <%= b.label %>
    </div>
  <% end %>
</div>

```

I do want the checkboxes to stay checked after form refresh but wanted to make sure it is a feature and not just a coincidence that is it working for me. 

Any information would be helpful, thanks!