When constructing the sidebar don't overide 'sidebar'
Instead specify 'sidebar_additional' and include it even if there
is a 'sidebar' defined.
Patch by: Sverre Rabbelier
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)