How to use the pycdlib.dates.DirectoryRecordDate function in pycdlib

def test_dirrecorddate_record_not_initialized():
    drdate = pycdlib.dates.DirectoryRecordDate()
    with pytest.raises(pycdlib.pycdlibexception.PyCdlibInternalError) as excinfo:
        drdate.record()
    assert(str(excinfo.value) == 'Directory Record Date not initialized')

def test_dirrecorddate_new_after_new():
    drdate = pycdlib.dates.DirectoryRecordDate()
    drdate.new()
    with pytest.raises(pycdlib.pycdlibexception.PyCdlibInternalError) as excinfo:
        drdate.new()
    assert(str(excinfo.value) == 'Directory Record Date already initialized')

def test_dirrecorddate_parse_after_parse():
    drdate = pycdlib.dates.DirectoryRecordDate()
    drdate.parse(b'\x76\x07\x12\x15\x21\x00\x00')
    with pytest.raises(pycdlib.pycdlibexception.PyCdlibInternalError) as excinfo:
        drdate.parse(b'\x76\x07\x12\x15\x21\x00\x00')
    assert(str(excinfo.value) == 'Directory Record Date already initialized')

if extent_location_le != utils.swab_32bit(extent_location_be):
            raise pycdlibexception.PyCdlibInvalidISO('Little-endian (%d) and big-endian (%d) extent location disagree' % (extent_location_le, utils.swab_32bit(extent_location_be)))
        self.orig_extent_loc = extent_location_le

        # Theoretically, we should check to make sure that the little endian
        # data length is the same as the big endian data length.  In practice,
        # though, we've seen ISOs where this is wrong.  Skip the check, and just
        # pick the little-endian as the 'actual' size, and hope for the best.

        self.data_length = data_length_le

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

        self.date = dates.DirectoryRecordDate()
        self.date.parse(dr_date)

        # OK, we've unpacked what we can from the beginning of the string.  Now
        # we have to use the len_fi to get the rest.

        self.parent = parent
        self.vd = vd

        if self.parent is None:
            self.is_root = True

            # A root directory entry should always be exactly 34 bytes.
            # However, we have seen ISOs in the wild that get this wrong, so we
            # elide a check for it.

            self.file_ident = bytes(bytearray([record[33]]))

length - The length of the data for this directory record.
         xa - True if this is an Extended Attribute record.
        Returns:
         Nothing.
        '''

        # Adding a new time should really be done when we are going to write
        # the ISO (in record()).  Ecma-119 9.1.5 says:
        #
        # 'This field shall indicate the date and the time of the day at which
        # the information in the Extent described by the Directory Record was
        # recorded.'
        #
        # We create it here just to have something in the field, but we'll
        # redo the whole thing when we are mastering.
        self.date = dates.DirectoryRecordDate()
        self.date.new()

        if length > 2**32 - 1:
            raise pycdlibexception.PyCdlibInvalidInput('Maximum supported file length is 2^32-1')

        self.data_length = length

        self.file_ident = name

        self.isdir = isdir

        self.seqnum = seqnum
        # For a new directory record entry, there is no original_extent_loc,
        # so we leave it at None.
        self.orig_extent_loc = None
        self.len_fi = len(self.file_ident)

# so we don't bother.

        (su_len, su_entry_version_unused,
         self.time_flags) = struct.unpack_from('=BBB', rrstr[:5], 2)
        if su_len < 5:
            raise pycdlibexception.PyCdlibInvalidISO('Not enough bytes in the TF record')

        tflen = 7
        if self.time_flags & (1 << 7):
            tflen = 17

        offset = 5
        for index, fieldname in enumerate(self.FIELDNAMES):
            if self.time_flags & (1 << index):
                if tflen == 7:
                    setattr(self, fieldname, dates.DirectoryRecordDate())
                elif tflen == 17:
                    setattr(self, fieldname, dates.VolumeDescriptorDate())
                getattr(self, fieldname).parse(rrstr[offset:offset + tflen])
                offset += tflen

        self._initialized = True

Returns:
         Nothing.
        '''
        if self._initialized:
            raise pycdlibexception.PyCdlibInternalError('TF record already initialized')

        self.time_flags = time_flags

        tflen = 7
        if self.time_flags & (1 << 7):
            tflen = 17

        for index, fieldname in enumerate(self.FIELDNAMES):
            if self.time_flags & (1 << index):
                if tflen == 7:
                    setattr(self, fieldname, dates.DirectoryRecordDate())
                elif tflen == 17:
                    setattr(self, fieldname, dates.VolumeDescriptorDate())
                getattr(self, fieldname).new()

        self._initialized = True