diff --git a/.github/workflows/code_check.yml b/.github/workflows/code_check.yml
index 0658e20..291e6ea 100644
--- a/.github/workflows/code_check.yml
+++ b/.github/workflows/code_check.yml
@@ -44,6 +44,24 @@ jobs:
       - name: Run PHPUnit
         run: vendor/bin/phpunit
 
+  phpmd:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: 7.4
+
+      - name: Install dependencies
+        run: composer install --prefer-dist --no-progress --no-suggest
+
+      - name: Run PHPMD
+        run: vendor/bin/phpmd src github phpmd.xml
+
   php-cs-fixer:
     runs-on: ubuntu-latest
 
@@ -66,3 +84,4 @@ jobs:
         uses: stefanzweifel/git-auto-commit-action@v4
         with:
           commit_message: Fix styling
+
diff --git a/composer.json b/composer.json
index 802e032..f714748 100644
--- a/composer.json
+++ b/composer.json
@@ -11,7 +11,8 @@
     "require-dev": {
         "phpunit/phpunit": "^9.6",
         "friendsofphp/php-cs-fixer": "^3.58",
-        "phpstan/phpstan": "^1.11"
+        "phpstan/phpstan": "^1.11",
+        "phpmd/phpmd": "^2.15"
     },
     "autoload": {
         "psr-4": {
diff --git a/composer.lock b/composer.lock
index 7f3f4c5..2253e1a 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "742b713e90945bc6ddfaa70138c1c1fc",
+    "content-hash": "4f36bf737f95f8b94aff9b17efeb91c1",
     "packages": [
         {
             "name": "guzzlehttp/guzzle",
@@ -1281,6 +1281,69 @@
             },
             "time": "2024-03-05T20:51:40+00:00"
         },
+        {
+            "name": "pdepend/pdepend",
+            "version": "2.16.2",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/pdepend/pdepend.git",
+                "reference": "f942b208dc2a0868454d01b29f0c75bbcfc6ed58"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/pdepend/pdepend/zipball/f942b208dc2a0868454d01b29f0c75bbcfc6ed58",
+                "reference": "f942b208dc2a0868454d01b29f0c75bbcfc6ed58",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=5.3.7",
+                "symfony/config": "^2.3.0|^3|^4|^5|^6.0|^7.0",
+                "symfony/dependency-injection": "^2.3.0|^3|^4|^5|^6.0|^7.0",
+                "symfony/filesystem": "^2.3.0|^3|^4|^5|^6.0|^7.0",
+                "symfony/polyfill-mbstring": "^1.19"
+            },
+            "require-dev": {
+                "easy-doc/easy-doc": "0.0.0|^1.2.3",
+                "gregwar/rst": "^1.0",
+                "squizlabs/php_codesniffer": "^2.0.0"
+            },
+            "bin": [
+                "src/bin/pdepend"
+            ],
+            "type": "library",
+            "extra": {
+                "branch-alias": {
+                    "dev-master": "2.x-dev"
+                }
+            },
+            "autoload": {
+                "psr-4": {
+                    "PDepend\\": "src/main/php/PDepend"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "description": "Official version of pdepend to be handled with Composer",
+            "keywords": [
+                "PHP Depend",
+                "PHP_Depend",
+                "dev",
+                "pdepend"
+            ],
+            "support": {
+                "issues": "https://github.com/pdepend/pdepend/issues",
+                "source": "https://github.com/pdepend/pdepend/tree/2.16.2"
+            },
+            "funding": [
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/pdepend/pdepend",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2023-12-17T18:09:59+00:00"
+        },
         {
             "name": "phar-io/manifest",
             "version": "2.0.4",
@@ -1399,6 +1462,89 @@
             },
             "time": "2022-02-21T01:04:05+00:00"
         },
+        {
+            "name": "phpmd/phpmd",
+            "version": "2.15.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/phpmd/phpmd.git",
+                "reference": "74a1f56e33afad4128b886e334093e98e1b5e7c0"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/phpmd/phpmd/zipball/74a1f56e33afad4128b886e334093e98e1b5e7c0",
+                "reference": "74a1f56e33afad4128b886e334093e98e1b5e7c0",
+                "shasum": ""
+            },
+            "require": {
+                "composer/xdebug-handler": "^1.0 || ^2.0 || ^3.0",
+                "ext-xml": "*",
+                "pdepend/pdepend": "^2.16.1",
+                "php": ">=5.3.9"
+            },
+            "require-dev": {
+                "easy-doc/easy-doc": "0.0.0 || ^1.3.2",
+                "ext-json": "*",
+                "ext-simplexml": "*",
+                "gregwar/rst": "^1.0",
+                "mikey179/vfsstream": "^1.6.8",
+                "squizlabs/php_codesniffer": "^2.9.2 || ^3.7.2"
+            },
+            "bin": [
+                "src/bin/phpmd"
+            ],
+            "type": "library",
+            "autoload": {
+                "psr-0": {
+                    "PHPMD\\": "src/main/php"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Manuel Pichler",
+                    "email": "github@manuel-pichler.de",
+                    "homepage": "https://github.com/manuelpichler",
+                    "role": "Project Founder"
+                },
+                {
+                    "name": "Marc Würth",
+                    "email": "ravage@bluewin.ch",
+                    "homepage": "https://github.com/ravage84",
+                    "role": "Project Maintainer"
+                },
+                {
+                    "name": "Other contributors",
+                    "homepage": "https://github.com/phpmd/phpmd/graphs/contributors",
+                    "role": "Contributors"
+                }
+            ],
+            "description": "PHPMD is a spin-off project of PHP Depend and aims to be a PHP equivalent of the well known Java tool PMD.",
+            "homepage": "https://phpmd.org/",
+            "keywords": [
+                "dev",
+                "mess detection",
+                "mess detector",
+                "pdepend",
+                "phpmd",
+                "pmd"
+            ],
+            "support": {
+                "irc": "irc://irc.freenode.org/phpmd",
+                "issues": "https://github.com/phpmd/phpmd/issues",
+                "source": "https://github.com/phpmd/phpmd/tree/2.15.0"
+            },
+            "funding": [
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/phpmd/phpmd",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2023-12-11T08:22:20+00:00"
+        },
         {
             "name": "phpstan/phpstan",
             "version": "1.11.4",
@@ -3520,6 +3666,85 @@
             ],
             "time": "2020-09-28T06:39:44+00:00"
         },
+        {
+            "name": "symfony/config",
+            "version": "v5.4.40",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/config.git",
+                "reference": "d4e1db78421163b98dd9971d247fd0df4a57ee5e"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/config/zipball/d4e1db78421163b98dd9971d247fd0df4a57ee5e",
+                "reference": "d4e1db78421163b98dd9971d247fd0df4a57ee5e",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=7.2.5",
+                "symfony/deprecation-contracts": "^2.1|^3",
+                "symfony/filesystem": "^4.4|^5.0|^6.0",
+                "symfony/polyfill-ctype": "~1.8",
+                "symfony/polyfill-php80": "^1.16",
+                "symfony/polyfill-php81": "^1.22"
+            },
+            "conflict": {
+                "symfony/finder": "<4.4"
+            },
+            "require-dev": {
+                "symfony/event-dispatcher": "^4.4|^5.0|^6.0",
+                "symfony/finder": "^4.4|^5.0|^6.0",
+                "symfony/messenger": "^4.4|^5.0|^6.0",
+                "symfony/service-contracts": "^1.1|^2|^3",
+                "symfony/yaml": "^4.4|^5.0|^6.0"
+            },
+            "suggest": {
+                "symfony/yaml": "To use the yaml reference dumper"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\Config\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Helps you find, load, combine, autofill and validate configuration values of any kind",
+            "homepage": "https://symfony.com",
+            "support": {
+                "source": "https://github.com/symfony/config/tree/v5.4.40"
+            },
+            "funding": [
+                {
+                    "url": "https://symfony.com/sponsor",
+                    "type": "custom"
+                },
+                {
+                    "url": "https://github.com/fabpot",
+                    "type": "github"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2024-05-31T14:33:22+00:00"
+        },
         {
             "name": "symfony/console",
             "version": "v5.4.40",
@@ -3619,6 +3844,95 @@
             ],
             "time": "2024-05-31T14:33:22+00:00"
         },
+        {
+            "name": "symfony/dependency-injection",
+            "version": "v5.4.40",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/symfony/dependency-injection.git",
+                "reference": "408b33326496030c201b8051b003e9e8cdb2efc9"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/symfony/dependency-injection/zipball/408b33326496030c201b8051b003e9e8cdb2efc9",
+                "reference": "408b33326496030c201b8051b003e9e8cdb2efc9",
+                "shasum": ""
+            },
+            "require": {
+                "php": ">=7.2.5",
+                "psr/container": "^1.1.1",
+                "symfony/deprecation-contracts": "^2.1|^3",
+                "symfony/polyfill-php80": "^1.16",
+                "symfony/polyfill-php81": "^1.22",
+                "symfony/service-contracts": "^1.1.6|^2"
+            },
+            "conflict": {
+                "ext-psr": "<1.1|>=2",
+                "symfony/config": "<5.3",
+                "symfony/finder": "<4.4",
+                "symfony/proxy-manager-bridge": "<4.4",
+                "symfony/yaml": "<4.4.26"
+            },
+            "provide": {
+                "psr/container-implementation": "1.0",
+                "symfony/service-implementation": "1.0|2.0"
+            },
+            "require-dev": {
+                "symfony/config": "^5.3|^6.0",
+                "symfony/expression-language": "^4.4|^5.0|^6.0",
+                "symfony/yaml": "^4.4.26|^5.0|^6.0"
+            },
+            "suggest": {
+                "symfony/config": "",
+                "symfony/expression-language": "For using expressions in service container configuration",
+                "symfony/finder": "For using double-star glob patterns or when GLOB_BRACE portability is required",
+                "symfony/proxy-manager-bridge": "Generate service proxies to lazy load them",
+                "symfony/yaml": ""
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Symfony\\Component\\DependencyInjection\\": ""
+                },
+                "exclude-from-classmap": [
+                    "/Tests/"
+                ]
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "MIT"
+            ],
+            "authors": [
+                {
+                    "name": "Fabien Potencier",
+                    "email": "fabien@symfony.com"
+                },
+                {
+                    "name": "Symfony Community",
+                    "homepage": "https://symfony.com/contributors"
+                }
+            ],
+            "description": "Allows you to standardize and centralize the way objects are constructed in your application",
+            "homepage": "https://symfony.com",
+            "support": {
+                "source": "https://github.com/symfony/dependency-injection/tree/v5.4.40"
+            },
+            "funding": [
+                {
+                    "url": "https://symfony.com/sponsor",
+                    "type": "custom"
+                },
+                {
+                    "url": "https://github.com/fabpot",
+                    "type": "github"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/symfony/symfony",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2024-05-31T14:33:22+00:00"
+        },
         {
             "name": "symfony/event-dispatcher",
             "version": "v5.4.40",
diff --git a/phpmd.xml b/phpmd.xml
new file mode 100644
index 0000000..8167ac0
--- /dev/null
+++ b/phpmd.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<ruleset name="My first PHPMD rule set"
+         xmlns="https://phpmd.org/xml/ruleset/1.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="https://phpmd.org/xml/ruleset/1.0.0
+                       http://phpmd.org/xml/ruleset_xml_schema_1.0.0.xsd"
+         xsi:noNamespaceSchemaLocation="
+                       http://phpmd.org/xml/ruleset_xml_schema_1.0.0.xsd">
+  <description>
+    My custom rule set that checks my code...
+  </description>
+
+  <rule ref="rulesets/codesize.xml" />
+  <rule ref="rulesets/cleancode.xml" />
+  <rule ref="rulesets/controversial.xml" />
+  <rule ref="rulesets/design.xml" />
+  <rule ref="rulesets/naming.xml" />
+  <rule ref="rulesets/unusedcode.xml" />
+</ruleset>