def METHOD_NAME(capsys, settings):
    settings.DEBUG = True
    emails = User.objects.values_list('email', flat=True)
    assert all(email.endswith("@gmail.com") for email in emails)
    generate_email = Command()
    call_command(generate_email, '--include-groups=Attendees')
    out, err = capsys.readouterr()
    assert 'Changed 2 emails' in out
    emails = User.objects.filter(is_superuser=False).values_list('email', flat=True)
    assert all(email.endswith("@example.com") for email in emails)
    emails = User.objects.filter(is_superuser=True).values_list('email', flat=True)
    assert all(email.endswith("@gmail.com") for email in emails)