def METHOD_NAME(
    tmpdir,  # type: Any
    header,  # type: bytes
    comment,  # type: bytes
):
    # type: (...) -> None
    zip_file = create_zipapp(tmpdir, comment=comment)
    zip_file_with_header = os.path.join(str(tmpdir), "zip_file_with_header")
    with open(zip_file, "rb") as in_fp, open(zip_file_with_header, "wb") as out_fp:
        out_fp.write(header)
        shutil.copyfileobj(in_fp, out_fp)
    zf = Zip.load(zip_file_with_header)
    assert bool(header) == zf.has_header
    with BytesIO() as out_fp:
        assert b"" == zf.isolate_header(out_fp)
        assert header == out_fp.getvalue()
    out_zip = os.path.join(str(tmpdir), "out.zip")
    with open(out_zip, "wb") as out_fp:
        zf.isolate_zip(out_fp)
    assert filecmp.cmp(zip_file, out_zip, shallow=False)
    assert_zipapp(out_zip, expected_comment=comment)