Iterating over items in search result view with django haystack MultiValueField

Question

If I have a MultiValueField on one of my search indexes and I want to display each value in the search results, how would I do that? It seems like something is not being formatted appropriately or I am somehow misunderstanding the MultiValueField.

class PageAttachmentIndex(indexes.SearchIndex):
 # This should reference search/indexes/pages/pageattachment_text.txt
 text      = indexes.CharField(document=True, use_template=True)
 title     = indexes.CharField(model_attr='name')
 page      = indexes.IntegerField(model_attr='page_id')
 attrs     = indexes.MultiValueField()
 file      = indexes.CharField(model_attr='file')
 filesize  = indexes.IntegerField(model_attr='file__size')
 timestamp = indexes.DateTimeField(model_attr='timestamp')
 url       = indexes.CharField(model_attr='page')

 def prepare_attrs(self, obj):
     """ Prepare the attributes for any file attachments on the 
         current page as specified in the M2M relationship. """
     # Add in attributes (assuming there's a M2M relationship to 
     # attachment attributes on the model.) Note that this will NOT 
     # get picked up by the automatic schema tools provided by haystack
     attributes = obj.attributes.all()
     return attributes

In leveraging this in my template view:

         {% if result.attrs|length %}    
         <div class="attributes">        
             <ul>        
             {% for a in result.attrs %}
                 <li class="{% cycle "clear" "" "" %}"><span class="name">{{ a.name }}</span>: <span class="value">{{ a.value }}</span></li>
             {% endfor %}
             </ul>
             <div class="clear"></div>
         </div>
         {% endif %}

This seems to return nothing for me :(