diff --git a/src/Utilities/Repository.php b/src/Utilities/Repository.php
index 65c07a9..b9d48b5 100644
--- a/src/Utilities/Repository.php
+++ b/src/Utilities/Repository.php
@@ -10,7 +10,6 @@ namespace Meritoo\Common\Utilities;
 
 use Doctrine\ORM\EntityRepository;
 use Doctrine\ORM\QueryBuilder;
-use ReflectionException;
 
 /**
  * Useful methods for repository
@@ -20,73 +19,143 @@ use ReflectionException;
  */
 class Repository
 {
+    /**
+     * Name of key responsible for sorting/position of an item in array
+     *
+     * @var string
+     */
+    const POSITION_KEY = 'position';
+
     /**
      * Replenishes positions of given items
      *
-     * @param array $items  The items
-     * @param bool  $asLast (optional) If is set to true, items are placed at the end (default behaviour). Otherwise
-     *                      - at top.
+     * @param array $items  Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @param bool  $asLast (optional) If is set to true, items are placed at the end (default behaviour). Otherwise -
+     *                      at top.
      * @param bool  $force  (optional) If is set to true, positions are set even there is no extreme position.
-     *                      Otherwise - if extreme position is not found (is null) replenishment is stopped / skipped
+     *                      Otherwise - if extreme position is unknown (is null) replenishment is stopped / skipped
      *                      (default behaviour).
-     *
-     * @throws ReflectionException
      */
-    public static function replenishPositions($items, $asLast = true, $force = false)
+    public static function replenishPositions(array &$items, $asLast = true, $force = false)
     {
         $position = self::getExtremePosition($items, $asLast);
 
+        /*
+         * Extreme position is unknown, but it's required?
+         * Use 0 as default/start value
+         */
         if (null === $position && $force) {
             $position = 0;
         }
 
-        if (null !== $position && !empty($items)) {
-            foreach ($items as $item) {
-                if (method_exists($item, 'getPosition')) {
-                    if (null === $item->getPosition()) {
-                        if ($asLast) {
-                            ++$position;
-                        } else {
-                            --$position;
-                        }
+        /*
+         * Extreme position is unknown or there are no items to sort?
+         * Nothing to do
+         */
+        if (null === $position || empty($items)) {
+            return;
+        }
 
-                        if (method_exists($item, 'setPosition')) {
-                            $item->setPosition($position);
-                        }
-                    }
-                }
+        foreach ($items as &$item) {
+            /*
+             * The item is not sortable?
+             */
+            if (!self::isSortable($item)) {
+                continue;
             }
+
+            /*
+             * Position has been set?
+             * Nothing to do
+             */
+            if (self::isSorted($item)) {
+                continue;
+            }
+
+            /*
+             * Calculate position
+             */
+            if ($asLast) {
+                ++$position;
+            } else {
+                --$position;
+            }
+
+            /*
+             * It's an object?
+             * Use proper method to set position
+             */
+            if (is_object($item)) {
+                $item->setPosition($position);
+                continue;
+            }
+
+            /*
+             * It's an array
+             * Use proper key to set position
+             */
+            $item[static::POSITION_KEY] = $position;
         }
     }
 
     /**
      * Returns extreme position (max or min) of given items
      *
-     * @param array $items The items
+     * @param array $items Objects who have "getPosition()" and "setPosition()" methods or arrays
      * @param bool  $max   (optional) If is set to true, maximum value is returned. Otherwise - minimum.
      * @return int
-     *
-     * @throws ReflectionException
      */
-    public static function getExtremePosition($items, $max = true)
+    public static function getExtremePosition(array $items, $max = true)
     {
+        /*
+         * No items?
+         * Nothing to do
+         */
+        if (empty($items)) {
+            return null;
+        }
+
         $extreme = null;
 
-        if (!empty($items)) {
-            foreach ($items as $item) {
-                if (Reflection::hasMethod($item, 'getPosition')) {
-                    $position = $item->getPosition();
+        foreach ($items as $item) {
+            /*
+             * The item is not sortable?
+             */
+            if (!self::isSortable($item)) {
+                continue;
+            }
 
-                    if ($max) {
-                        if ($position > $extreme) {
-                            $extreme = $position;
-                        }
-                    } else {
-                        if ($position < $extreme) {
-                            $extreme = $position;
-                        }
-                    }
+            $position = null;
+
+            /*
+             * Let's grab the position
+             */
+            if (is_object($item)) {
+                $position = $item->getPosition();
+            } elseif (array_key_exists(static::POSITION_KEY, $item)) {
+                $position = $item[static::POSITION_KEY];
+            }
+
+            /*
+             * Maximum value is expected?
+             */
+            if ($max) {
+                /*
+                 * Position was found and it's larger than previously found position (the extreme position)?
+                 */
+                if (null === $extreme || (null !== $position && $position > $extreme)) {
+                    $extreme = $position;
                 }
+
+                continue;
+            }
+
+            /*
+             * Minimum value is expected here.
+             * Position was found and it's smaller than previously found position (the extreme position)?
+             */
+            if (null === $extreme || (null !== $position && $position < $extreme)) {
+                $extreme = $position;
             }
         }
 
@@ -113,4 +182,54 @@ class Repository
             ->createQueryBuilder($alias)
             ->orderBy(sprintf('%s.%s', $alias, $property), $direction);
     }
+
+    /**
+     * Returns information if given item is sortable
+     *
+     * Sortable means it's an:
+     * - array
+     * or
+     * - object and has getPosition() and setPosition()
+     *
+     * @param mixed $item An item to verify (object who has "getPosition()" and "setPosition()" methods or an array)
+     * @return bool
+     */
+    private static function isSortable($item)
+    {
+        return is_array($item)
+            ||
+            (
+                is_object($item)
+                &&
+                Reflection::hasMethod($item, 'getPosition')
+                &&
+                Reflection::hasMethod($item, 'setPosition')
+            );
+    }
+
+    /**
+     * Returns information if given item is sorted (position has been set)
+     *
+     * @param mixed $item An item to verify (object who has "getPosition()" and "setPosition()" methods or an array)
+     * @return bool
+     */
+    private static function isSorted($item)
+    {
+        /*
+         * Given item is not sortable?
+         */
+        if (!self::isSortable($item)) {
+            return false;
+        }
+
+        /*
+         * It's an object or it's an array
+         * and position has been set?
+         */
+
+        return
+            (is_object($item) && null !== $item->getPosition())
+            ||
+            (is_array($item) && isset($item[static::POSITION_KEY]));
+    }
 }
diff --git a/tests/Utilities/Repository/Sortable.php b/tests/Utilities/Repository/Sortable.php
new file mode 100644
index 0000000..0e4f2db
--- /dev/null
+++ b/tests/Utilities/Repository/Sortable.php
@@ -0,0 +1,66 @@
+<?php
+
+/**
+ * (c) Meritoo.pl, http://www.meritoo.pl
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Meritoo\Common\Test\Utilities\Repository;
+
+/**
+ * Sortable object/entity.
+ * Used for testing the Repository class.
+ *
+ * @author    Krzysztof Niziol <krzysztof.niziol@meritoo.pl>
+ * @copyright Meritoo.pl
+ */
+class Sortable
+{
+    /**
+     * Position used while sorting
+     *
+     * @var int
+     */
+    private $position;
+
+    /**
+     * Class constructor
+     *
+     * @param int $position (optional) Position used while sorting
+     */
+    public function __construct($position = null)
+    {
+        $this->position = $position;
+    }
+
+    /**
+     * Returns position used while sorting
+     *
+     * @return int
+     */
+    public function getPosition()
+    {
+        return $this->position;
+    }
+
+    /**
+     * Sets position used while sorting
+     *
+     * @param int $position Position used while sorting
+     */
+    public function setPosition($position)
+    {
+        $this->position = $position;
+    }
+
+    /**
+     * Returns representation of object as string
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return sprintf('%s (position: %d)', self::class, $this->getPosition());
+    }
+}
diff --git a/tests/Utilities/RepositoryTest.php b/tests/Utilities/RepositoryTest.php
new file mode 100644
index 0000000..3739a30
--- /dev/null
+++ b/tests/Utilities/RepositoryTest.php
@@ -0,0 +1,603 @@
+<?php
+
+/**
+ * (c) Meritoo.pl, http://www.meritoo.pl
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Meritoo\Common\Test\Utilities;
+
+use Generator;
+use Meritoo\Common\Test\Base\BaseTestCase;
+use Meritoo\Common\Test\Utilities\Repository\Sortable;
+use Meritoo\Common\Utilities\Repository;
+use stdClass;
+
+/**
+ * Test case of the useful methods for repository
+ *
+ * @author    Krzysztof Niziol <krzysztof.niziol@meritoo.pl>
+ * @copyright Meritoo.pl
+ */
+class RepositoryTest extends BaseTestCase
+{
+    public function testConstructor()
+    {
+        static::assertHasNoConstructor(Repository::class);
+    }
+
+    public function testReplenishPositionsWithoutItems()
+    {
+        $items = [];
+        Repository::replenishPositions($items);
+
+        static::assertEquals([], $items);
+    }
+
+    public function testReplenishPositionsUsingNotSortableObjects()
+    {
+        $before = [
+            new stdClass(),
+            new stdClass(),
+            new stdClass(),
+        ];
+
+        $after = [
+            new stdClass(),
+            new stdClass(),
+            new stdClass(),
+        ];
+
+        /*
+         * Using defaults
+         */
+        Repository::replenishPositions($before);
+        static::assertEquals($before, $after);
+
+        /*
+         * Place items at the top
+         */
+        Repository::replenishPositions($before, false);
+        static::assertEquals($before, $after);
+
+        /*
+         * Set positions even there is no extreme position (at the end)
+         */
+        Repository::replenishPositions($before, true, true);
+        static::assertEquals($before, $after);
+
+        /*
+         * Set positions even there is no extreme position (at the top)
+         */
+        Repository::replenishPositions($before, false, true);
+        static::assertEquals($before, $after);
+    }
+
+    /**
+     * @param array $items Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @dataProvider provideArraysWithoutExtremePosition
+     */
+    public function testReplenishPositionsUsingArraysWithoutExtremePosition(array $items)
+    {
+        Repository::replenishPositions($items);
+        static::assertEquals($items, $items);
+
+        Repository::replenishPositions($items, false);
+        static::assertEquals($items, $items);
+    }
+
+    /**
+     * @param array $items    Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @param bool  $asLast   If is set to true, items are placed at the end (default behaviour). Otherwise - at top.
+     * @param array $expected Items with replenished positions
+     *
+     * @dataProvider provideArraysWithoutExtremePosition
+     */
+    public function testReplenishPositionsUsingArraysWithoutExtremePositionForce(array $items, $asLast, array $expected)
+    {
+        Repository::replenishPositions($items, $asLast, true);
+        static::assertEquals($expected, $items);
+    }
+
+    /**
+     * @param array $items    Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @param bool  $asLast   If is set to true, items are placed at the end (default behaviour). Otherwise - at top.
+     * @param array $expected Items with replenished positions
+     *
+     * @dataProvider provideArraysWithExtremePosition
+     */
+    public function testReplenishPositionsUsingArraysWithExtremePositionForce(array $items, $asLast, array $expected)
+    {
+        Repository::replenishPositions($items, $asLast, true);
+        static::assertEquals($expected, $items);
+    }
+
+    /**
+     * @param array $items Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @dataProvider provideObjectsWithoutExtremePosition
+     */
+    public function testReplenishPositionsUsingObjectsWithoutExtremePosition(array $items)
+    {
+        Repository::replenishPositions($items);
+        static::assertEquals($items, $items);
+
+        Repository::replenishPositions($items, false);
+        static::assertEquals($items, $items);
+    }
+
+    /**
+     * @param array $items    Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @param bool  $asLast   If is set to true, items are placed at the end (default behaviour). Otherwise - at top.
+     * @param array $expected Items with replenished positions
+     *
+     * @dataProvider provideObjectsWithoutExtremePosition
+     */
+    public function testReplenishPositionsUsingObjectsWithoutExtremePositionForce(array $items, $asLast, array $expected)
+    {
+        Repository::replenishPositions($items, $asLast, true);
+        static::assertEquals($expected, $items);
+    }
+
+    /**
+     * @param array $items    Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @param bool  $asLast   If is set to true, items are placed at the end (default behaviour). Otherwise - at top.
+     * @param array $expected Items with replenished positions
+     *
+     * @dataProvider provideObjectsWithExtremePosition
+     */
+    public function testReplenishPositionsUsingObjectsWithExtremePositionForce(array $items, $asLast, array $expected)
+    {
+        Repository::replenishPositions($items, $asLast, true);
+        static::assertEquals($expected, $items);
+    }
+
+    public function testGetExtremePositionWithoutItems()
+    {
+        static::assertNull(Repository::getExtremePosition([]));
+        static::assertNull(Repository::getExtremePosition([], false));
+    }
+
+    /**
+     * @param array $items    Objects who have "getPosition()" and "setPosition()" methods or arrays
+     * @param bool  $max      (optional) If is set to true, maximum value is returned. Otherwise - minimum.
+     * @param int   $expected Extreme position (max or min) of given items
+     *
+     * @dataProvider provideArraysWithoutExtremePositionToGetExtremePosition
+     */
+    public function testGetExtremePositionUsingArraysWithoutExtremePosition(array $items, $max, $expected)
+    {
+        static::assertEquals($expected, Repository::getExtremePosition($items, $max));
+    }
+
+    public function testGetExtremePositionUsingObjects()
+    {
+    }
+
+    public function testGetEntityOrderedQueryBuilder()
+    {
+    }
+
+    /**
+     * Provides arrays without extreme position used to replenish positions of them
+     *
+     * @return Generator
+     */
+    public function provideArraysWithoutExtremePosition()
+    {
+        yield[
+            [
+                [],
+                [],
+            ],
+            true,
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [
+                    Repository::POSITION_KEY => 2,
+                ],
+            ],
+        ];
+
+        yield[
+            [
+                [],
+                [],
+            ],
+            false,
+            [
+                [
+                    Repository::POSITION_KEY => -1,
+                ],
+                [
+                    Repository::POSITION_KEY => -2,
+                ],
+            ],
+        ];
+
+        yield[
+            [
+                [
+                    'lorem' => 'ipsum',
+                    'dolor',
+                    'sit'   => 1,
+                ],
+                [
+                    'abc' => 'def',
+                    'ghi' => null,
+                    'jkl' => 10,
+                ],
+            ],
+            true,
+            [
+                [
+                    'lorem'                  => 'ipsum',
+                    'dolor',
+                    'sit'                    => 1,
+                    Repository::POSITION_KEY => 1,
+                ],
+                [
+                    'abc'                    => 'def',
+                    'ghi'                    => null,
+                    'jkl'                    => 10,
+                    Repository::POSITION_KEY => 2,
+                ],
+            ],
+        ];
+
+        yield[
+            [
+                [
+                    'lorem' => 'ipsum',
+                    'dolor',
+                    'sit'   => 1,
+                ],
+                [
+                    'abc' => 'def',
+                    'ghi' => null,
+                    'jkl' => 10,
+                ],
+            ],
+            false,
+            [
+                [
+                    'lorem'                  => 'ipsum',
+                    'dolor',
+                    'sit'                    => 1,
+                    Repository::POSITION_KEY => -1,
+                ],
+                [
+                    'abc'                    => 'def',
+                    'ghi'                    => null,
+                    'jkl'                    => 10,
+                    Repository::POSITION_KEY => -2,
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Provides arrays with extreme position used to replenish positions of them
+     *
+     * @return Generator
+     */
+    public function provideArraysWithExtremePosition()
+    {
+        yield[
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [],
+                [],
+            ],
+            true,
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [
+                    Repository::POSITION_KEY => 2,
+                ],
+                [
+                    Repository::POSITION_KEY => 3,
+                ],
+            ],
+        ];
+
+        yield[
+            [
+                [],
+                [],
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+            ],
+            true,
+            [
+                [
+                    Repository::POSITION_KEY => 2,
+                ],
+                [
+                    Repository::POSITION_KEY => 3,
+                ],
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+            ],
+        ];
+
+        yield[
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [],
+                [],
+            ],
+            false,
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [
+                    Repository::POSITION_KEY => 0,
+                ],
+                [
+                    Repository::POSITION_KEY => -1,
+                ],
+            ],
+        ];
+
+        yield[
+            [
+
+                [],
+                [],
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+            ],
+            false,
+            [
+                [
+                    Repository::POSITION_KEY => 0,
+                ],
+                [
+                    Repository::POSITION_KEY => -1,
+                ],
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * Provides objects without extreme position used to replenish positions of them
+     *
+     * @return Generator
+     */
+    public function provideObjectsWithoutExtremePosition()
+    {
+        yield[
+            [
+                new Sortable(),
+                new Sortable(),
+                new Sortable(),
+            ],
+            true,
+            [
+                new Sortable(1),
+                new Sortable(2),
+                new Sortable(3),
+            ],
+        ];
+
+        yield[
+            [
+                new Sortable(),
+                new Sortable(),
+                new Sortable(),
+            ],
+            false,
+            [
+                new Sortable(-1),
+                new Sortable(-2),
+                new Sortable(-3),
+            ],
+        ];
+    }
+
+    /**
+     * Provides objects with extreme position used to replenish positions of them
+     *
+     * @return Generator
+     */
+    public function provideObjectsWithExtremePosition()
+    {
+        yield[
+            [
+                new Sortable(1),
+                new Sortable(),
+                new Sortable(),
+            ],
+            true,
+            [
+                new Sortable(1),
+                new Sortable(2),
+                new Sortable(3),
+            ],
+        ];
+
+        yield[
+            [
+                new Sortable(),
+                new Sortable(1),
+                new Sortable(),
+            ],
+            true,
+            [
+                new Sortable(2),
+                new Sortable(1),
+                new Sortable(3),
+            ],
+        ];
+
+        yield[
+            [
+                new Sortable(1),
+                new Sortable(),
+                new Sortable(),
+            ],
+            false,
+            [
+                new Sortable(1),
+                new Sortable(0),
+                new Sortable(-1),
+            ],
+        ];
+    }
+
+    /**
+     * Provides arrays without extreme position used to get extreme position
+     *
+     * @return Generator
+     */
+    public function provideArraysWithoutExtremePositionToGetExtremePosition()
+    {
+        yield[
+            [],
+            false,
+            null,
+        ];
+
+        yield[
+            [],
+            true,
+            null,
+        ];
+
+        yield[
+            [
+                [
+                    'lorem' => 'ipsum',
+                    'dolor',
+                    'sit'   => 1,
+                ],
+                [
+                    'abc' => 'def',
+                    'ghi' => null,
+                    'jkl' => 10,
+                ],
+            ],
+            true,
+            null,
+        ];
+
+        yield[
+            [
+                [
+                    'lorem' => 'ipsum',
+                    'dolor',
+                    'sit'   => 1,
+                ],
+                [
+                    'abc' => 'def',
+                    'ghi' => null,
+                    'jkl' => 10,
+                ],
+            ],
+            false,
+            null,
+        ];
+    }
+
+    /**
+     * Provides arrays with extreme position used to get extreme position
+     *
+     * @return Generator
+     */
+    public function provideArraysWithExtremePositionToGetExtremePosition()
+    {
+        yield[
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [],
+                [],
+            ],
+            true,
+            1,
+        ];
+
+        yield[
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [],
+                [],
+            ],
+            false,
+            1,
+        ];
+
+        yield[
+            [
+                [],
+                [],
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+            ],
+            true,
+            1,
+        ];
+
+        yield[
+            [
+                [],
+                [],
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+            ],
+            false,
+            1,
+        ];
+
+        yield[
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [],
+                [
+                    Repository::POSITION_KEY => 2,
+                ],
+                [],
+            ],
+            true,
+            1,
+        ];
+
+        yield[
+            [
+                [
+                    Repository::POSITION_KEY => 1,
+                ],
+                [],
+                [
+                    Repository::POSITION_KEY => 2,
+                ],
+                [],
+            ],
+            false,
+            2,
+        ];
+    }
+}