sub _open_sxc_fh($self, $fh, $member, %options) {
    my $zip = Archive::Zip->new();
    my $status = $zip->readFromFileHandle($fh);
    $status == AZ_OK
        or croak "Read error from zip";
    my $content = $zip->memberNamed($member);
    if( ! defined $content ) {
        if( $options{ optional }) {
            return;
        } else {
            croak "Want to read $member' but it doesn't exist!";
        }
    }
    $content->rewindData();
    my $stream = $content->fh;
    1 if eof($stream); # reset eof state of $stream?! Is that a bug? Where?
    binmode $stream => ':gzip(none)';
    return $stream
}