diff --git a/Account/Account.php b/Account/Account.php
index 09d0a7f4d..fd40e379f 100644
--- a/Account/Account.php
+++ b/Account/Account.php
@@ -94,18 +94,18 @@ class Account implements ArrayableInterface, \JsonSerializable
     /**
      * Last activity.
      *
-     * @var null|\DateTime
+     * @var \DateTime
      * @since 1.0.0
      */
-    protected ?\DateTime $lastActive = null;
+    protected \DateTime $lastActive;
 
     /**
      * Last activity.
      *
-     * @var null|\DateTime
+     * @var \DateTime
      * @since 1.0.0
      */
-    protected ?\DateTime $createdAt = null;
+    protected \DateTime $createdAt;
 
     /**
      * Groups.
@@ -145,7 +145,7 @@ class Account implements ArrayableInterface, \JsonSerializable
      * @var Localization
      * @since 1.0.0
      */
-    protected ?Localization $l11n = null;
+    protected Localization $l11n;
 
     use PermissionHandlingTrait;
 
diff --git a/Algorithm/Sort/BucketSort.php b/Algorithm/Sort/BucketSort.php
index ae8cfdb8b..383f1ba7e 100644
--- a/Algorithm/Sort/BucketSort.php
+++ b/Algorithm/Sort/BucketSort.php
@@ -29,6 +29,10 @@ class BucketSort
         $buckets = [];
         $M       = $list[0]::max($list);
 
+        if ($bucketCount < 1) {
+            return [];
+        }
+
         foreach ($list as $element) {
             $buckets[(int) \floor(($bucketCount - 1) * $element->getValue() / $M)][] = $element;
         }
diff --git a/Algorithm/Sort/CycleSort.php b/Algorithm/Sort/CycleSort.php
index f68b98517..1c0d07a39 100644
--- a/Algorithm/Sort/CycleSort.php
+++ b/Algorithm/Sort/CycleSort.php
@@ -77,6 +77,6 @@ class CycleSort implements SortInterface
             }
         }
 
-        return $order === SortOrder::ASC ? $list : \array_reverse($list, false);;
+        return $order === SortOrder::ASC ? $list : \array_reverse($list, false);
     }
 }
diff --git a/Algorithm/Sort/FlashSort.php b/Algorithm/Sort/FlashSort.php
index e69de29bb..14ab8e464 100644
--- a/Algorithm/Sort/FlashSort.php
+++ b/Algorithm/Sort/FlashSort.php
@@ -0,0 +1,117 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package    phpOMS\Algorithm\Sort;
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       https://orange-management.org
+ */
+declare(strict_types=1);
+
+namespace phpOMS\Algorithm\Sort;
+
+/**
+ * FlashSort class.
+ *
+ * @package    phpOMS\Algorithm\Sort;
+ * @license    OMS License 1.0
+ * @link       https://orange-management.org
+ * @since      1.0.0
+ */
+class FlashSort implements SortInterface
+{
+    public static function sort(array $list, int $order = SortOrder::ASC) : array
+    {
+        $n = \count($list);
+        $i = 0;
+        $j = 0;
+        $k = 0;
+        $m = 0.43 * $n;
+
+        if ($m > 262143) {
+            $m = 262143;
+        }
+
+        $l = \array_fill(0, $n, 0);
+        $anmin = $list[0];
+        $anmax = $anmin;
+        $nmax = 0;
+        $nmove = 0;
+        $lk = 0;
+
+        $kmin  = null;
+        $kmax  = null;
+
+        // todo: replace >>> with Numeric::uRightShift
+
+        for ($i = 0; (($i += 2) - $n) >>> 31;) {
+            if ((($kmax = $list[$i - 1])->getValue() - ($kmin = $list[$i])->getValue()) >>> 31) {
+                if (($kmax->getValue() - $anmin->getValue()) >>> 31) {
+                    $anmin = $list[$i - 1];
+                }
+
+                if (($anmax->getValue() - $kmin->getValue()) >>> 31) {
+                    $anmax = $list[$i];
+                    $nmax  = $i;
+                }
+            } else {
+                if (($kmin->getValue() - $anmin->getValue()) >>> 31) {
+                    $anmin = $list[$i];
+                }
+
+                if (($anmax->getValue() - $kmin->getValue()) >>> 31) {
+                    $anmax = $list[$i - 1];
+                    $nmax  = $i - 1;
+                }
+            }
+        }
+
+        if ((--$i - $n) >>> 31) {
+            if ((($k = $list[$i])->getValue() - $anmin->getValue()) >>> 31) {
+                $anmin = $list[$i];
+            } elseif (($anmax->getValue() - $k->getValue()) >>> 31) {
+                $anmax = $list[$i];
+                $nmax  = $i;
+            }
+        }
+
+        if ($anmin->getValue() === $anmax->getValue()) {
+            return $list;
+        }
+
+        $c1 = (($m - 1) << 13) / ($anmax->getValue() - $anmin->getValue());
+
+        for ($i = -1; (++$i - $n) >>> 31;) {
+            ++$l[($c1 * ($list[$i]->getValue() - $anmin->getValue())) >> 13];
+        }
+
+        $lk = $l[0];
+        for ($k = 0; (++$k - $m) >>> 31;) {
+            $lk = ($l[$k] += $lk);
+        }
+
+        $hold = $anmax;
+        $list[$nmax] = $list[0];
+        $list[0] = $hold;
+
+        $flash = null;
+        $j = 0;
+        $k = ($m - 1);
+        $i = ($n - 1);
+
+        while (($nmove - $i) >>> 31) {
+            while ($j !== $lk) {
+                $k = ($c1 * ($list[(++$j)]->getValue() - $anmin->getValue())) >> 13;
+            }
+
+            $flash = $a[$j];
+            $lk = $l[$k];
+
+            while ($j !== $lk)
+        }
+    }
+}
diff --git a/ApplicationAbstract.php b/ApplicationAbstract.php
index 2bc5ef5c8..06540556f 100644
--- a/ApplicationAbstract.php
+++ b/ApplicationAbstract.php
@@ -14,18 +14,19 @@ declare(strict_types=1);
 
 namespace phpOMS;
 
-use phpOMS\DataStorage\Database\DatabasePool;
-use phpOMS\Localization\L11nManager;
+use Model\CoreSettings;
 use phpOMS\Router\Router;
-use phpOMS\DataStorage\Session\SessionInterface;
-use phpOMS\DataStorage\Cookie\CookieJar;
+use phpOMS\Log\FileLogger;
+use phpOMS\Event\EventManager;
 use phpOMS\Module\ModuleManager;
 use phpOMS\Dispatcher\Dispatcher;
-use phpOMS\DataStorage\Cache\CachePool;
-use Model\CoreSettings;
-use phpOMS\Event\EventManager;
 use phpOMS\Account\AccountManager;
-use phpOMS\Log\FileLogger;
+use phpOMS\Localization\L11nManager;
+use phpOMS\Localization\Localization;
+use phpOMS\DataStorage\Cache\CachePool;
+use phpOMS\DataStorage\Cookie\CookieJar;
+use phpOMS\DataStorage\Database\DatabasePool;
+use phpOMS\DataStorage\Session\SessionInterface;
 
 /**
  * Application class.
diff --git a/Event/EventManager.php b/Event/EventManager.php
index 031a0374a..66672f9b7 100644
--- a/Event/EventManager.php
+++ b/Event/EventManager.php
@@ -52,10 +52,10 @@ final class EventManager implements \Countable
     /**
      * Dispatcher.
      *
-     * @var DispatcherInterface|Object<dispatch>
+     * @var DispatcherInterface
      * @since 1.0.0
      */
-    private ?DispatcherInterface $dispatcher = null;
+    private DispatcherInterface $dispatcher;
 
     /**
      * Constructor.
diff --git a/Message/Http/Request.php b/Message/Http/Request.php
index 144e5fbc8..50339aa67 100644
--- a/Message/Http/Request.php
+++ b/Message/Http/Request.php
@@ -89,7 +89,7 @@ final class Request extends RequestAbstract
      */
     private function init() : void
     {
-        if ($this->uri === null) {
+        if (!isset($this->uri)) {
             $this->initCurrentRequest();
             $this->lock();
             $this->cleanupGlobals();
diff --git a/Message/RequestAbstract.php b/Message/RequestAbstract.php
index a14cb5bd5..fb3ad4c9f 100644
--- a/Message/RequestAbstract.php
+++ b/Message/RequestAbstract.php
@@ -29,10 +29,10 @@ abstract class RequestAbstract implements MessageInterface
     /**
      * Uri.
      *
-     * @var null|UriInterface
+     * @var UriInterface
      * @since 1.0.0
      */
-    protected ?UriInterface $uri = null;
+    protected UriInterface $uri;
 
     /**
      * Request method.
@@ -85,10 +85,10 @@ abstract class RequestAbstract implements MessageInterface
     /**
      * Request header.
      *
-     * @var null|HeaderAbstract
+     * @var HeaderAbstract
      * @since 1.0.0
      */
-    protected ?HeaderAbstract $header = null;
+    protected HeaderAbstract $header;
 
     /**
      * Get request uri.
diff --git a/Message/ResponseAbstract.php b/Message/ResponseAbstract.php
index c361cb783..3c733f3ed 100644
--- a/Message/ResponseAbstract.php
+++ b/Message/ResponseAbstract.php
@@ -35,10 +35,10 @@ abstract class ResponseAbstract implements MessageInterface, \JsonSerializable
     /**
      * Header.
      *
-     * @var null|HeaderAbstract
+     * @var HeaderAbstract
      * @since 1.0.0
      */
-    protected ?HeaderAbstract $header = null;
+    protected HeaderAbstract $header;
 
     /**
      * Get response by ID.
diff --git a/Model/Html/Head.php b/Model/Html/Head.php
index c47d55166..9ef80b373 100644
--- a/Model/Html/Head.php
+++ b/Model/Html/Head.php
@@ -66,10 +66,10 @@ class Head implements RenderableInterface
     /**
      * Page meta.
      *
-     * @var null|Meta
+     * @var Meta
      * @since 1.0.0
      */
-    private ?Meta $meta = null;
+    private Meta $meta;
 
     /**
      * html style.
diff --git a/tests/Algorithm/PathFinding/JumpPointSearchTest.php b/tests/Algorithm/PathFinding/JumpPointSearchTest.php
new file mode 100644
index 000000000..0808e9b94
--- /dev/null
+++ b/tests/Algorithm/PathFinding/JumpPointSearchTest.php
@@ -0,0 +1,59 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.4
+ *
+ * @package    tests
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       https://orange-management.org
+ */
+ declare(strict_types=1);
+
+namespace phpOMS\tests\Algorithm\Sort;
+
+use phpOMS\Algorithm\PathFinding\Grid;
+use phpOMS\Algorithm\PathFinding\MovementType;
+use phpOMS\Algorithm\PathFinding\HeuristicType;
+use phpOMS\Algorithm\PathFinding\JumpPointNode;
+use phpOMS\Algorithm\PathFinding\JumpPointSearch;
+
+require_once __DIR__ . '/../../Autoloader.php';
+
+/**
+ * @testdox phpOMS\tests\Algorithm\PathFinding: jump point search test
+ *
+ * @internal
+ */
+class JumpPointSearchTest extends \PHPUnit\Framework\TestCase
+{
+    private array $gridArray = [
+        [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,],
+        [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0,],
+        [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,],
+        [0, 0, 9, 9, 9, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0,],
+        [0, 0, 0, 0, 9, 9, 9, 9, 9, 0, 9, 0, 0, 0, 0,],
+        [0, 0, 1, 0, 9, 0, 0, 0, 0, 0, 9, 0, 9, 9, 9,],
+        [0, 0, 0, 0, 9, 0, 0, 9, 9, 9, 9, 0, 0, 0, 0,],
+        [0, 0, 9, 9, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,],
+        [0, 0, 0, 9, 0, 0, 0, 9, 0, 0, 9, 9, 9, 9, 0,],
+        [0, 0, 0, 9, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0,],
+        [0, 0, 0, 9, 0, 0, 0, 9, 0, 0, 9, 9, 0, 0, 0,],
+        [0, 0, 0, 0, 0, 9, 9, 9, 0, 0, 9, 2, 0, 0, 0,],
+        [0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 9, 9, 0, 0, 0,],
+        [0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0,],
+        [0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0,],
+    ];
+
+    public function testPathFinding() : void
+    {
+        $grid = Grid::createGridFromArray($this->gridArray, JumpPointNode::class);
+        $path = JumpPointSearch::findPath(
+            2, 5,
+            11, 11,
+            $grid, HeuristicType::EUCLIDEAN, MovementType::DIAGONAL
+        );
+    }
+}