adding facet.mincount to django-haystack

gistfile1.py

#the backend
class MySolrBackend(SolrSearchBackend):
    def build_search_kwargs(self, *args, **kwargs):
        facet_mincount = kwargs.pop('facet_mincount', None)
        search_kwargs = super(AiSolrBackend, self).build_search_kwargs(*args, **kwargs)
        
        if facet_mincount is not None:
            search_kwargs['facet'] = 'on'
            search_kwargs['facet.mincount'] = facet_mincount
            
class MyEngine(SolrEngine):
    backend = MySolrBackend
    
#in settings
HAYSTACK_CONNECTIONS = {
    'default': {
        'ENGINE': 'search.backends.MyEngine',
        'URL': 'http://127.0.0.1:8983/solr'
    },
}

#custom queryset
class MySearchQuerySet(SearchQuerySet):
    def facet_mincount(self, mincount):
        """Sets mincount for facet result."""
        clone = self._clone()
        clone.query.set_facet_mincount(mincount)
        return clone