'Auto-created many-to-many through tables referencing a parent model are
correctly found by the delete cascade when a child of that parent is
deleted.
Refs #14896.'

def test_inheritance(self):

    r = Researcher.objects.create()
    email = Email.objects.create(label='office-email', email_address='carl@science.edu')
    r.contacts.add(email)
    email.delete()
