sub {
    my $schema = $_->{oneOf} = [];

    push @$schema, { enum => [ keys $_->{'$defs'}->%* ] };

    for my $generic ( keys $_->{'$defs'}->%* ) {
        push @$schema, {
            type => 'object',
            properties => {
                generic => { const => $generic },
                subclass => { enum => $_->{'$defs'}{$generic} }
            }
        }
    }

    return $_;
}