bbp_update_group_forum_ids( type $group_id,  $forum_ids = array() )

function bbp_update_group_forum_ids( $group_id = 0, $forum_ids = array() ) {

	// Use current group if none is set
	if ( empty( $group_id ) )
		$group_id = bp_get_current_group_id();

	// Trim out any empties
	$forum_ids = array_filter( $forum_ids );

	// Get the forums
	return groups_update_groupmeta( $group_id, 'forum_id', $forum_ids );
}