diff --git a/Algorithm/Knapsack/Continuous.php b/Algorithm/Knapsack/Continuous.php
index cf6a5adf7..cd804914c 100644
--- a/Algorithm/Knapsack/Continuous.php
+++ b/Algorithm/Knapsack/Continuous.php
@@ -35,6 +35,21 @@ final class Continuous
     {
     }
 
+    /**
+     * Comparing items
+     *
+     * @param Item[] $a Item
+     * @param Item[] $b Item
+     *
+     * @return int
+     *
+     * @since 1.0.0
+     */
+    private static function continuousComparator(array $a, array $b) : int
+    {
+        return $b['item']->getValue() / $b['item']->getCost() <=> $a['item']->getValue() / $a['item']->getCost();
+    }
+
     /**
      * Fill the backpack with items
      *
@@ -47,9 +62,7 @@ final class Continuous
      */
     public static function solve(array $items, BackpackInterface $backpack) : BackpackInterface
     {
-        \usort($items, function($a, $b) {
-            return $a['item']->getValue() / $a['item']->getCost() < $b['item']->getValue() / $b['item']->getCost();
-        });
+        \usort($items, ['self', 'continuousComparator']);
 
         $availableSpace = $backpack->getMaxCost();
 
diff --git a/DataStorage/Database/DataMapperAbstract.php b/DataStorage/Database/DataMapperAbstract.php
index 9203fac40..fb6891159 100644
--- a/DataStorage/Database/DataMapperAbstract.php
+++ b/DataStorage/Database/DataMapperAbstract.php
@@ -363,11 +363,13 @@ class DataMapperAbstract implements DataMapperInterface
     public static function clear() : void
     {
         // clear parent and objects
-        if (static::class === self::$parentMapper) {
-            self::$parentMapper = null;
-            self::$conditionals = [];
-            self::$relations    = RelationType::ALL;
+        if (static::class !== self::$parentMapper) {
+            return;
         }
+
+        self::$parentMapper = null;
+        self::$conditionals = [];
+        self::$relations    = RelationType::ALL;
     }
 
     /**