bp_get_total_unread_messages_count( int $user_id )

	function bp_get_total_unread_messages_count( $user_id = 0 ) {

		/**
		 * Filters the unread messages count for the current inbox.
		 *
		 * @since BuddyPress 1.0.0
		 *
		 * @param int $value Unread messages count for the current inbox.
		 */
		return apply_filters( 'bp_get_total_unread_messages_count', BP_Messages_Thread::get_inbox_count( $user_id ) );
	}