sub add_record {
    my ($self, $data) = @_;
    my @record;
    for my $key (keys %$data) {
        my $att_key = $key =~ /[^0-9]/ ? "name" : "fid";
        ( my $att_val = lc($key) ) =~ s/[^a-z0-9]/_/g;
        push @record, {
            tag   => "field", 
            atts  => { $att_key => $att_val },
            value => $data->{$key},
        };
    }
    return post_api("API_AddRecord", \@record);
}