sub new {
        my ($self, %args) = @_;
        my @required = qw(NAME AGE RANK URL);

        my %cfg = map {uc $_ => $args{$_}} keys %args;

        for my $req (qw(NAME AGE RANK URL)) {
                croak "Required argument $req not found"
                        unless exists $cfg{$req};
        }

        return bless \%cfg, $self;
}