try_skipping(QPDFTokenizer& tokenizer, PointerHolder<InputSource> is,
             size_t max_len, char const* what, Finder& f)
{
    std::cout << "skipping to " << what << std::endl;
    qpdf_offset_t offset = is->tell();
    if (! is->findFirst(what, offset, 0, f))
    {
        std::cout << what << " not found" << std::endl;
        is->seek(offset, SEEK_SET);
    }
}
try_skipping(QPDFTokenizer& tokenizer, PointerHolder<InputSource> is,
             size_t max_len, char const* what, Finder& f)
{
    std::cout << "skipping to " << what << std::endl;
    qpdf_offset_t offset = is->tell();
    if (! is->findFirst(what, offset, 0, f))
    {
        std::cout << what << " not found" << std::endl;
        is->seek(offset, SEEK_SET);
    }
}