code: def get_query(self, q, request):
          
          return Person.objects.filter(
              Q(username__icontains=q)
              | Q(short_name__icontains=q)
              | Q(full_name__icontains=q)
          )
docs: return a query set searching for the query string q
              either implement this method yourself or set the search_field
              in the LookupChannel class definition