bbp_update_topic_topic_id( int $topic_id )

function bbp_update_topic_topic_id( $topic_id = 0 ) {
	$topic_id = bbp_get_topic_id( $topic_id );

	update_post_meta( $topic_id, '_bbp_topic_id', (int) $topic_id );

	return apply_filters( 'bbp_update_topic_topic_id', (int) $topic_id );
}