sub new {

    my ( $class, @attributes ) = @_;
    my $self = {@attributes};


    #  make sure we got valid argument keys
    if ( @attributes ) {
        my $key_hash = {@attributes};
        my @keys = keys %$key_hash;

        my @invalid_attribute_key =
            grep {
                my $tested_attributes = $_;
                not grep {
                    $tested_attributes eq $_
                } qw(attribute_1 attribute_2 attribute_3);
            } @keys;

        croak "invalid attribute key(s) in constructor: @invalid_attribute_key" if @invalid_attribute_key;
    }

    bless $self, $class;
    return $self;

}