This can't be moved to Try::Tiny due to the closures within causing
    # leaks on any version of Perl prior to 5.18.
    # https://perl5.git.perl.org/perl.git/commitdiff/a0d2bbd5c
    my $error = do { #catch
        local $@;
        local $\; # protect the print below from surprises
        eval { # try
            if (!defined($arg) || !$response->is_success) {
                $response->{default_add_content} = 1;
            }
            elsif (!ref($arg) && length($arg)) {
                open(my $fh, ">", $arg) or die "Can't write to '$arg': $!";
                binmode($fh);
                push(@{$response->{handlers}{response_data}}, {
                    callback => sub {
                        print $fh $_[3] or die "Can't write to '$arg': $!";
                        1;