Does libarchive now not support multi-threaded decompression of xz?

[klop]

//set option

char attr[64];
sprintf_s(attr, "xz:threads=%d", 8);
archive_read_set_options(a, attr);

call stacks

archive_set_filter_option

_archive_set_either_option

archive_set_option

_archive_set_options

archive_read_set_options

//do not implemented

static int
archive_set_filter_option(struct archive *_a, const char *m, const char *o,
    const char *v)
{
(void)_a; /* UNUSED */
(void)o; /* UNUSED */
(void)v; /* UNUSED */

/* If the filter name didn't match, return a special code for
 * _archive_set_option[s]. */
if (m != NULL)
return ARCHIVE_WARN - 1;
return ARCHIVE_WARN;
}

As far as I know, liblzma itself supports multi-threaded decompression. It provides the lzma_stream_decoder_mt interface. Is it not implemented by libarchive?