ult: True)

    :param bool strict_types:
        If set to true, types will be checked to be exact. Derived classes
        from serializable types will not be serialized and will be
        treated as unsupported type and forwarded to default.
        Additionally tuples will not be serialized as lists.
        This is useful when trying to implement accurate serialization
        for python types.

    :param bool datetime:
        If set to true, datetime with tzinfo is packed into Timestamp type.
        Note that the tzinfo is stripped in the timestamp.
        You can get UTC datetime with `timestamp=3` option of the Unpacker.
        (Python 2 is not supported).

    :param str unicode_errors:
        The error handler for encoding unicode. (default: 'strict')
        DO NOT USE THIS!!  This option is kept for very specific usage.

    Example of streaming deserialize from file-like object::

        unpacker = Unpacker(file_like)
        for o in unpacker:
            process(o)

    Example of streaming deserialize from socket::

        unpacker = Unpacker()
        while True:
            buf = sock.recv(1024**2)
            if not buf:
                break
            unpacker.feed(buf)
            for o in unpacker:
                process(o)

    Raises ``ExtraData`` when *packed* contains extra bytes.
    Raises ``OutOfData`` when *packed* is incomplete.
    Raises ``FormatError`` when *packed* is not valid msgpack.
    Raises ``StackError`` when *packed* contains too nested.
    Other exceptions can be raised during unpacking.
    NFTc