How to use the pycdlib.pycdlibexception.PyCdlibInvalidISO function in pycdlib

if self.file_structure_version != 1:
                self.file_structure_version = 1
        elif self._vd_type == VOLUME_DESCRIPTOR_TYPE_SUPPLEMENTARY:
            if self.file_structure_version not in (1, 2):
                raise pycdlibexception.PyCdlibInvalidISO('File structure version expected to be 1')
        # According to Ecma-119, 8.4.31, the second unused field should be 0.
        if unused2 != 0:
            raise pycdlibexception.PyCdlibInvalidISO('data in 2nd unused field not zero')
        # According to Ecma-119, the last 653 bytes of the VD should be all 0.
        # However, we have seen ISOs in the wild that do not follow this, so
        # relax the check.

        # Check to make sure that the little-endian and big-endian versions
        # of the parsed data agree with each other.
        if space_size_le != utils.swab_32bit(space_size_be):
            raise pycdlibexception.PyCdlibInvalidISO('Little-endian and big-endian space size disagree')
        self.space_size = space_size_le

        if set_size_le != utils.swab_16bit(set_size_be):
            raise pycdlibexception.PyCdlibInvalidISO('Little-endian and big-endian set size disagree')
        self.set_size = set_size_le

        if seqnum_le != utils.swab_16bit(seqnum_be):
            raise pycdlibexception.PyCdlibInvalidISO('Little-endian and big-endian seqnum disagree')
        self.seqnum = seqnum_le

        if logical_block_size_le != utils.swab_16bit(logical_block_size_be):
            raise pycdlibexception.PyCdlibInvalidISO('Little-endian and big-endian logical block size disagree')
        self.log_block_size = logical_block_size_le

        if path_table_size_le != utils.swab_32bit(path_table_size_be):
            raise pycdlibexception.PyCdlibInvalidISO('Little-endian and big-endian path table size disagree')

raise pycdlibexception.PyCdlibInvalidISO('PX record big and little-endian file user ID do not agree')

        if posix_file_group_id_le != utils.swab_32bit(posix_file_group_id_be):
            raise pycdlibexception.PyCdlibInvalidISO('PX record big and little-endian file group ID do not agree')

        # In Rock Ridge 1.09 and 1.10, there is no serial number so the su_len
        # is 36, while in Rock Ridge 1.12, there is an 8-byte serial number so
        # su_len is 44.
        if su_len == 36:
            posix_file_serial_number_le = 0
        elif su_len == 44:
            (posix_file_serial_number_le,
             posix_file_serial_number_be) = struct.unpack_from('

entry_list.cl_record.parse(recslice)
            elif rtype == b'PL':
                entry_list.pl_record = RRPLRecord()
                entry_list.pl_record.parse(recslice)
            elif rtype == b'RE':
                entry_list.re_record = RRRERecord()
                entry_list.re_record.parse(recslice)
            elif rtype == b'TF':
                entry_list.tf_record = RRTFRecord()
                entry_list.tf_record.parse(recslice)
            elif rtype == b'SF':
                entry_list.sf_record = RRSFRecord()
                entry_list.sf_record.parse(recslice)
                sf_record_length = len(recslice)
            else:
                raise pycdlibexception.PyCdlibInvalidISO('Unknown SUSP record')
            offset += su_len
            left -= su_len

        # Now let's determine the version of Rock Ridge that we have (1.09,
        # 1.10, or 1.12).  Unfortunately, there is no direct information from
        # Rock Ridge, so we infer it from what is present.  In an ideal world,
        # the following table would tell us:
        #
        # | Feature/Rock Ridge version |      1.09     |      1.10     |      1.12     |
        # +----------------------------+---------------+---------------+---------------+
        # |    Has RR Record?          | True or False |     False     |     False     |
        # |    Has ES Record?          |     False     |     False     | True or False |
        # |    Has SF Record?          |     False     | True or False | True or False |
        # |    PX Record length        |      36       |      36       |      44       |
        # |    SF Record length        |     N/A       |      12       |      21       |
        # |    ER Desc string          |  RRIP_1991A   |  RRIP_1991A   |  IEEE_P1282   |

raise pycdlibexception.PyCdlibInvalidISO('Parent of the entry did not have Rock Ridge, ISO is corrupt')

            if self.file_ident == b'\x00':
                # If we are adding the dot directory, increment the parent
                # file links and our file links.
                self.parent.rock_ridge.add_to_file_links()
                self.rock_ridge.add_to_file_links()
            elif self.file_ident == b'\x01':
                # If we are adding the dotdot directory, copy the file links
                # from the dot directory of the grandparent.
                if self.parent.parent is None:
                    raise pycdlibexception.PyCdlibInternalError('Grandparent of the entry did not exist; this cannot be')
                if not self.parent.children:
                    raise pycdlibexception.PyCdlibInvalidISO('Grandparent of the entry did not have a dot entry; ISO is corrupt')
                if self.parent.parent.children[0].rock_ridge is None:
                    raise pycdlibexception.PyCdlibInvalidISO('Grandparent dotdot entry did not have Rock Ridge; ISO is corrupt')
                self.rock_ridge.copy_file_links(self.parent.parent.children[0].rock_ridge)
            else:
                # For all other entries, increment the parents file links
                # and the parents dot file links.
                self.parent.rock_ridge.add_to_file_links()

                if not self.parent.children:
                    raise pycdlibexception.PyCdlibInvalidISO('Parent of the entry did not have a dot entry; ISO is corrupt')
                if self.parent.children[0].rock_ridge is None:
                    raise pycdlibexception.PyCdlibInvalidISO('Dot child of the parent did not have a dot entry; ISO is corrupt')
                self.parent.children[0].rock_ridge.add_to_file_links()

# If we are adding the dotdot directory, copy the file links
                # from the dot directory of the grandparent.
                if self.parent.parent is None:
                    raise pycdlibexception.PyCdlibInternalError('Grandparent of the entry did not exist; this cannot be')
                if not self.parent.children:
                    raise pycdlibexception.PyCdlibInvalidISO('Grandparent of the entry did not have a dot entry; ISO is corrupt')
                if self.parent.parent.children[0].rock_ridge is None:
                    raise pycdlibexception.PyCdlibInvalidISO('Grandparent dotdot entry did not have Rock Ridge; ISO is corrupt')
                self.rock_ridge.copy_file_links(self.parent.parent.children[0].rock_ridge)
            else:
                # For all other entries, increment the parents file links
                # and the parents dot file links.
                self.parent.rock_ridge.add_to_file_links()

                if not self.parent.children:
                    raise pycdlibexception.PyCdlibInvalidISO('Parent of the entry did not have a dot entry; ISO is corrupt')
                if self.parent.children[0].rock_ridge is None:
                    raise pycdlibexception.PyCdlibInvalidISO('Dot child of the parent did not have a dot entry; ISO is corrupt')
                self.parent.children[0].rock_ridge.add_to_file_links()

# If this is a directory, we have to manipulate the file links
        # appropriately.
        if self.parent.is_root:
            if self.file_ident == b'\x00' or self.file_ident == b'\x01':
                # For the dot and dotdot children of the root, add one
                # directly to their Rock Ridge links.
                self.rock_ridge.add_to_file_links()
            else:
                # For all other children of the root, make sure to add one
                # to each of the dot and dotdot entries.
                if len(self.parent.children) < 2:
                    raise pycdlibexception.PyCdlibInvalidISO('Expected at least 2 children of the root directory record, saw %d' % (len(self.parent.children)))

                if self.parent.children[0].rock_ridge is None:
                    raise pycdlibexception.PyCdlibInvalidISO('Dot child of directory has no Rock Ridge; ISO is corrupt')
                self.parent.children[0].rock_ridge.add_to_file_links()

                if self.parent.children[1].rock_ridge is None:
                    raise pycdlibexception.PyCdlibInvalidISO('Dot-dot child of directory has no Rock Ridge; ISO is corrupt')
                self.parent.children[1].rock_ridge.add_to_file_links()
        else:
            if self.parent.rock_ridge is None:
                raise pycdlibexception.PyCdlibInvalidISO('Parent of the entry did not have Rock Ridge, ISO is corrupt')

            if self.file_ident == b'\x00':
                # If we are adding the dot directory, increment the parent
                # file links and our file links.
                self.parent.rock_ridge.add_to_file_links()
                self.rock_ridge.add_to_file_links()
            elif self.file_ident == b'\x01':
                # If we are adding the dotdot directory, copy the file links

while True:
            if left == 0:
                break
            if left == 1:
                # There may be a padding byte on the end.
                if bytes(bytearray([record[offset]])) != b'\x00':
                    raise pycdlibexception.PyCdlibInvalidISO('Invalid pad byte')
                break
            if left < 4:
                raise pycdlibexception.PyCdlibInvalidISO('Not enough bytes left in the System Use field')

            (rtype, su_len, su_entry_version) = struct.unpack_from('=2sBB', record[:offset + 4], offset)
            if su_entry_version != SU_ENTRY_VERSION:
                raise pycdlibexception.PyCdlibInvalidISO('Invalid RR version %d!' % su_entry_version)
            if su_len == 0:
                raise pycdlibexception.PyCdlibInvalidISO('Zero size for Rock Ridge entry length')

            recslice = record[offset:]

            if rtype in (b'SP', b'RR', b'CE', b'PX', b'ST', b'ER',
                         b'PN', b'CL', b'PL', b'RE', b'TF', b'SF'):
                recname = rtype.decode('utf-8').lower() + '_record'
                if self.has_entry(recname):
                    raise pycdlibexception.PyCdlibInvalidISO('Only single %s record supported' % (rtype.decode('utf-8')))

            if rtype == b'SP':
                if left < 7 or not is_first_dir_record_of_root:
                    raise pycdlibexception.PyCdlibInvalidISO('Invalid SUSP SP record')

                # OK, this is the first Directory Record of the root
                # directory, which means we should check it for the SUSP/RR
                # extension, which is exactly 7 bytes and starts with 'SP'.

(tag_unused, icb_tag, self.uid, self.gid, self.perms, self.file_link_count,
         record_format, record_display_attrs, record_len,
         self.info_len, self.log_block_recorded, access_time, mod_time,
         attr_time, checkpoint, extended_attr_icb, impl_ident, self.unique_id,
         self.len_extended_attrs, len_alloc_descs) = struct.unpack_from(self.FMT, data, 0)

        self.desc_tag = desc_tag

        self.icb_tag = UDFICBTag()
        self.icb_tag.parse(icb_tag)

        if record_format != 0:
            raise pycdlibexception.PyCdlibInvalidISO('File Entry record format is not 0')

        if record_display_attrs != 0:
            raise pycdlibexception.PyCdlibInvalidISO('File Entry record display attributes is not 0')

        if record_len != 0:
            raise pycdlibexception.PyCdlibInvalidISO('File Entry record length is not 0')

        self.access_time = UDFTimestamp()
        self.access_time.parse(access_time)

        self.mod_time = UDFTimestamp()
        self.mod_time.parse(mod_time)

        self.attr_time = UDFTimestamp()
        self.attr_time.parse(attr_time)

        if checkpoint != 1:
            raise pycdlibexception.PyCdlibInvalidISO('Only DVD Read-only disks supported')