'Check that list_display_links is a unique subset of list_display.'

def _check_list_display_links(self, obj):

    from django.contrib.admin.options import ModelAdmin
    if (obj.list_display_links is None):
        return []
    elif (not isinstance(obj.list_display_links, (list, tuple))):
        return must_be('a    list,    a    tuple,    or    None', option='list_display_links', obj=obj, id='admin.E110')
    elif (obj.get_list_display.__func__ is ModelAdmin.get_list_display):
        return list(chain.from_iterable((self._check_list_display_links_item(obj, field_name, ('list_display_links[%d]' % index)) for (index, field_name) in enumerate(obj.list_display_links))))
    return []
