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

def concatenate(n):
        output_pdf = Pdf.new()
        for i in range(n):
            print(i)
            pdf_page = Pdf.open(resources / 'pal.pdf')
            output_pdf.pages.extend(pdf_page.pages)
        output_pdf.save(outdir / '{}.pdf'.format(n))

def test_add_foreign_twice(graph, outpdf):
    out = Pdf.new()
    out.pages.append(out.copy_foreign(graph.pages[0]))
    assert len(out.pages) == 1
    out.pages.append(out.copy_foreign(graph.pages[0]))
    assert len(out.pages) == 2
    out.save(outpdf)

def _repeat_page(pdf_in, page, count, pdf_out):
        for dup in range(count):
            pdf_new = Pdf.new()
            pdf_new.pages.append(pdf_in.pages[page])
            pdf_out.pages.extend(pdf_new.pages)
        return pdf_out

def test_stack_abuse():
    p = pikepdf.Pdf.new()

    stream = pikepdf.Stream(p, b'q ' * 35)
    with pytest.warns(None) as record:
        pdfinfo.info._interpret_contents(stream)
    assert 'overflowed' in str(record[0].message)

    stream = pikepdf.Stream(p, b'q Q Q Q Q')
    with pytest.warns(None) as record:
        pdfinfo.info._interpret_contents(stream)
    assert 'underflowed' in str(record[0].message)

    stream = pikepdf.Stream(p, b'q ' * 135)
    with pytest.warns(None):
        with pytest.raises(RuntimeError):
            pdfinfo.info._interpret_contents(stream)

def test_create_form_xobjects(outdir):
    pdf = Pdf.new()

    font = pdf.make_indirect(
        Object.parse(
            b"""
            <<
                /Type /Font
                /Subtype /Type1
                /Name /F1
                /BaseFont /Helvetica
                /Encoding /WinAnsiEncoding
            >>
        """
        )
    )

    width, height = 100, 100

def test_repeat_using_intermediate(graph, outpdf):
    def _repeat_page(pdf_in, page, count, pdf_out):
        for dup in range(count):
            pdf_new = Pdf.new()
            pdf_new.pages.append(pdf_in.pages[page])
            pdf_out.pages.extend(pdf_new.pages)
        return pdf_out

    with Pdf.new() as out:
        _repeat_page(graph, 0, 3, out)
        assert len(out.pages) == 3
        out.save(outpdf)

def test_image_roundtrip(outdir, w, h, pixeldata, cs, bpc):
    pdf = Pdf.new()

    image_data = pixeldata * (w * h)

    image = Stream(pdf, image_data)
    image.Type = Name('/XObject')
    image.Subtype = Name('/Image')
    image.ColorSpace = Name(cs)
    image.BitsPerComponent = bpc
    image.Width = w
    image.Height = h

    xobj = {'/Im1': image}
    resources = {'/XObject': xobj}
    mediabox = [0, 0, 100, 100]
    stream = b'q 100 0 0 100 0 0 cm /Im1 Do Q'
    contents = Stream(pdf, stream)

def export(input_files, pages, file_out):
    pdf_output = pikepdf.Pdf.new()
    pdf_input = [pikepdf.open(p.copyname) for p in input_files]
    for row in pages:
        current_page = pdf_input[row[2] - 1].pages[row[3] - 1]
        angle = row[6]
        angle0 = current_page.Rotate if '/Rotate' in current_page else 0
        if angle != 0:
            current_page.Rotate = angle + angle0
        cropped = _mediabox(row, angle, angle0, current_page.MediaBox)
        if cropped:
            current_page.MediaBox = cropped
        pdf_output.pages.append(current_page)
    with pdf_output.open_metadata() as outmeta:
        outmeta.load_from_docinfo(pdf_input[0].docinfo)
        for k, v in pdf_input[0].open_metadata().items():
            if _pikepdf_meta_is_valid(v):
                outmeta[k] = v