pocketmine\block\RedstoneWire::getPowerSources PHP Method

    public function getPowerSources(RedstoneWire $wire, array $powers = [], array $hasUpdated = [], $isStart = false)
    {
        if (!$isStart) {
            $wire->meta = 0;
            $wire->getLevel()->setBlock($wire, $wire, true, false);
            $wire->deactivate();
        }
        $hasChecked = [Vector3::SIDE_WEST => false, Vector3::SIDE_EAST => false, Vector3::SIDE_NORTH => false, Vector3::SIDE_SOUTH => false];
        $hash = Level::blockHash($wire->x, $wire->y, $wire->z);
        if (!isset($hasUpdated[$hash])) {
            $hasUpdated[$hash] = true;
        } else {
            return [$powers, $hasUpdated];
        }
        //check blocks around
        foreach ($hasChecked as $side => $bool) {
            /** @var RedstoneWire $block */
            $block = $wire->getSide($side);
            if ($block instanceof RedstoneSource) {
                if ($block->isActivated($wire)) {
                    if ($block->getId() != $this->id) {
                        $powers[] = $block;
                    } else {
                        $result = $this->getPowerSources($block, $powers, $hasUpdated);
                        $powers = $result[0];
                        $hasUpdated = $result[1];
                    }
                    $hasChecked[$side] = true;
                }
            }
        }
        //check blocks above
        $baseBlock = $wire->add(0, 1, 0);
        foreach ($hasChecked as $side => $bool) {
            if (!$bool) {
                $block = $this->getLevel()->getBlock($baseBlock->getSide($side));
                if ($block instanceof RedstoneSource) {
                    if ($block->isActivated($wire)) {
                        if ($block->getId() == $this->id) {
                            $result = $this->getPowerSources($block, $powers, $hasUpdated);
                            $powers = $result[0];
                            $hasUpdated = $result[1];
                            $hasChecked[$side] = true;
                        }
                    }
                }
            }
        }
        //check blocks below
        $baseBlock = $wire->add(0, -1, 0);
        foreach ($hasChecked as $side => $bool) {
            if (!$bool) {
                $block = $this->getLevel()->getBlock($baseBlock->getSide($side));
                if ($block instanceof RedstoneSource) {
                    if ($block->isActivated($wire)) {
                        if ($block->getId() == $this->id) {
                            $result = $this->getPowerSources($block, $powers, $hasUpdated);
                            $powers = $result[0];
                            $hasUpdated = $result[1];
                            $hasChecked[$side] = true;
                        }
                    }
                }
            }
        }
        return [$powers, $hasUpdated];
    }