'Index over trimmed group types.'

def index(self, request, group_types):

    group_types_list = [self.show(request, group_type, True) for group_type in group_types]
    group_type_links = self._get_collection_links(request, group_types, 'group_types')
    group_types_dict = dict(group_types=group_types_list)
    if group_type_links:
        group_types_dict['group_type_links'] = group_type_links
    return group_types_dict
