pocketmine\block\RedstoneWire::getUnconnectedSide PHP Method

    public function getUnconnectedSide()
    {
        $connected = [];
        $notConnected = [];
        foreach ($this->getConnectedWires() as $key => $bool) {
            if ($bool) {
                $connected[] = $key;
            } else {
                $notConnected[] = $key;
            }
        }
        if (count($connected) == 1) {
            return [$this->getOppositeSide($connected[0]), $connected];
        } elseif (count($connected) == 3) {
            return [$notConnected[0], $connected];
        } else {
            return [false, $connected];
        }
    }