How to use the pikepdf.Pdf.open function in pikepdf

def test_open_pdf_no_password_but_needed(self, resources):
        with pytest.raises(PasswordError):
            Pdf.open(resources / 'graph-encrypted.pdf')

def test_memory(self, resources):
        pdf = (resources / 'pal-1bit-trivial.pdf').read_bytes()
        with pytest.raises(Exception):
            pdf = Pdf.open(pdf)

def graph(resources):
    # Has XMP and docinfo, all standard format XMP
    return Pdf.open(resources / 'graph.pdf')

def test_roundtrip(filename):
    try:
        pdf = Pdf.open(filename)
    except PasswordError:
        return
    with pdf.open_metadata() as xmp:
        for k in xmp.keys():
            if not 'Date' in k:
                xmp[k] = 'A'
    assert '

def test_update_info(graph, outdir):
    new_title = '我敢打赌，你只是想看看这意味着什么'
    graph.docinfo['/Title'] = new_title
    graph.save(outdir / 'out.pdf')

    new = Pdf.open(outdir / 'out.pdf')
    assert new.docinfo['/Title'] == new_title
    assert graph.docinfo['/Author'] == new.docinfo['/Author']

    with pytest.raises(ValueError):
        new.docinfo = Dictionary({'/Keywords': 'bob'})

    new.docinfo = graph.make_indirect(Dictionary({'/Keywords': 'bob'}))
    assert new.docinfo.is_indirect, "/Info must be an indirect object"