reworked CypherMap to work with array under the hood

Author: transistive

psalm.xml

@@ -41,6 +41,12 @@
                 <directory name="src"/>
             </errorLevel>
         </DeprecatedInterface>
+        <UnusedForeachValue>
+            <errorLevel type="suppress">
+                <directory name="tests"/>
+                <directory name="src"/>
+            </errorLevel>
+        </UnusedForeachValue>
     </issueHandlers>
     <stubs>
         <file name="./vendor/vimeo/psalm/stubs/ext-ds.phpstub"/>

src/Databags/Pair.php

@@ -1,8 +1,54 @@
 <?php
 
+declare(strict_types=1);
+
+/*
+ * This file is part of the Laudis Neo4j package.
+ *
+ * (c) Laudis technologies <http://laudis.tech>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
 namespace Laudis\Neo4j\Databags;
 
-class Pair
+/**
+ * @template TKey
+ * @template TValue
+ *
+ * @psalm-immutable
+ */
+final class Pair
 {
+    /** @var TKey */
+    private $key;
+    /** @var TValue */
+    private $value;
+
+    /**
+     * @param TKey   $key
+     * @param TValue $value
+     */
+    public function __construct($key, $value)
+    {
+        $this->key = $key;
+        $this->value = $value;
+    }
+
+    /**
+     * @return TKey
+     */
+    public function getKey()
+    {
+        return $this->key;
+    }
 
+    /**
+     * @return TValue
+     */
+    public function getValue()
+    {
+        return $this->value;
+    }
 }