Use key_name instead of link_id
Some entities do not have a link_id, but all entities are guaranteed
to have a key_name (or an id).
from django.core.management.base import NoArgsCommand
class Command(NoArgsCommand):
help = "Validates all installed models."
requires_model_validation = False
def handle_noargs(self, **options):
self.validate(display_num_errors=True)