diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5bde662..ce744b6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,7 +19,9 @@ jobs:
         php-version: [
           '7.4',
           '8.0',
-          '8.1'
+          '8.1',
+          '8.2',
+          '8.3',
         ]
 
     steps:
@@ -56,7 +58,7 @@ jobs:
         run: vendor/bin/parallel-lint src/
 
       - name: Run CodeStyle checks
-        run: PHP_CS_FIXER_IGNORE_ENV=1 vendor/bin/php-cs-fixer fix src --allow-risky=yes --diff --dry-run
+        run: PHP_CS_FIXER_IGNORE_ENV=1 vendor/bin/php-cs-fixer check --allow-risky=yes --diff
 
       - name: Run PHPStan
         run: vendor/bin/phpstan analyze -clear-result-cache -c phpstan.neon src/ --no-progress
diff --git a/composer.json b/composer.json
index f59c8f9..013cde9 100644
--- a/composer.json
+++ b/composer.json
@@ -38,10 +38,10 @@
   "require-dev": {
     "phpunit/phpunit": "^9.6.13",
     "phpstan/phpstan": "^1.10.41",
-    "friendsofphp/php-cs-fixer": "^v3.38.0",
-    "php-parallel-lint/php-parallel-lint": "^1.3.2",
-    "enlightn/security-checker": "^1.10.0",
-    "symfony/routing": "^4.4.44 || ^5.0.0"
+    "friendsofphp/php-cs-fixer": "*",
+    "php-parallel-lint/php-parallel-lint": "*",
+    "enlightn/security-checker": "*",
+    "symfony/routing": "^4.4.44 || ^5.0.0 || ^6.0.0"
   },
   "autoload": {
     "psr-4": {
@@ -55,7 +55,8 @@
   },
   "scripts": {
     "test": "vendor/bin/phpunit --testdox tests",
-    "sniff-fix": "vendor/bin/php-cs-fixer fix",
+    "sniff": "PHP_CS_FIXER_IGNORE_ENV=1 vendor/bin/php-cs-fixer check --allow-risky=yes --diff",
+    "sniff-fix": "PHP_CS_FIXER_IGNORE_ENV=1 vendor/bin/php-cs-fixer fix --allow-risky=yes --diff",
     "phpstan": "vendor/bin/phpstan analyze"
   }
 }
diff --git a/src/CXml/Endpoint.php b/src/CXml/Endpoint.php
index 5029978..ab70d4e 100644
--- a/src/CXml/Endpoint.php
+++ b/src/CXml/Endpoint.php
@@ -29,9 +29,6 @@ public function __construct(
         $this->logger = $logger ?? new NullLogger();
     }
 
-    /**
-     * @throws Exception\CXmlException
-     */
     public function parseAndProcessStringAsCXml(string $xml, Context $context = null): ?CXml
     {
         $this->logger->info('Processing incoming CXml message', ['xml' => $xml]);
diff --git a/src/CXml/Exception/CXmlConflictException.php b/src/CXml/Exception/CXmlConflictException.php
index 8bfd174..3bad6cd 100644
--- a/src/CXml/Exception/CXmlConflictException.php
+++ b/src/CXml/Exception/CXmlConflictException.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Exception;
 
-class CXmlConflictException extends CXmlException {}
+class CXmlConflictException extends CXmlException
+{
+}
diff --git a/src/CXml/Exception/CXmlExpectationFailedException.php b/src/CXml/Exception/CXmlExpectationFailedException.php
index 4988e43..2815c86 100644
--- a/src/CXml/Exception/CXmlExpectationFailedException.php
+++ b/src/CXml/Exception/CXmlExpectationFailedException.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Exception;
 
-class CXmlExpectationFailedException extends CXmlException {}
+class CXmlExpectationFailedException extends CXmlException
+{
+}
diff --git a/src/CXml/Exception/CXmlNotAcceptableException.php b/src/CXml/Exception/CXmlNotAcceptableException.php
index 2383d94..b9f0346 100644
--- a/src/CXml/Exception/CXmlNotAcceptableException.php
+++ b/src/CXml/Exception/CXmlNotAcceptableException.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Exception;
 
-class CXmlNotAcceptableException extends CXmlException {}
+class CXmlNotAcceptableException extends CXmlException
+{
+}
diff --git a/src/CXml/Exception/CXmlNotImplementedException.php b/src/CXml/Exception/CXmlNotImplementedException.php
index 3b02b66..d4b25e0 100644
--- a/src/CXml/Exception/CXmlNotImplementedException.php
+++ b/src/CXml/Exception/CXmlNotImplementedException.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Exception;
 
-class CXmlNotImplementedException extends CXmlException {}
+class CXmlNotImplementedException extends CXmlException
+{
+}
diff --git a/src/CXml/Exception/CXmlPreconditionFailedException.php b/src/CXml/Exception/CXmlPreconditionFailedException.php
index ecf9676..9a2b106 100644
--- a/src/CXml/Exception/CXmlPreconditionFailedException.php
+++ b/src/CXml/Exception/CXmlPreconditionFailedException.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Exception;
 
-class CXmlPreconditionFailedException extends CXmlException {}
+class CXmlPreconditionFailedException extends CXmlException
+{
+}
diff --git a/src/CXml/Model/Message/MessagePayloadInterface.php b/src/CXml/Model/Message/MessagePayloadInterface.php
index ae4bca7..1164f80 100644
--- a/src/CXml/Model/Message/MessagePayloadInterface.php
+++ b/src/CXml/Model/Message/MessagePayloadInterface.php
@@ -4,4 +4,6 @@
 
 use CXml\Model\PayloadInterface;
 
-interface MessagePayloadInterface extends PayloadInterface {}
+interface MessagePayloadInterface extends PayloadInterface
+{
+}
diff --git a/src/CXml/Model/PayloadInterface.php b/src/CXml/Model/PayloadInterface.php
index bbdaeda..b9b8999 100644
--- a/src/CXml/Model/PayloadInterface.php
+++ b/src/CXml/Model/PayloadInterface.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Model;
 
-interface PayloadInterface {}
+interface PayloadInterface
+{
+}
diff --git a/src/CXml/Model/Request/ProfileRequest.php b/src/CXml/Model/Request/ProfileRequest.php
index 1c61347..5a4acc4 100644
--- a/src/CXml/Model/Request/ProfileRequest.php
+++ b/src/CXml/Model/Request/ProfileRequest.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Model\Request;
 
-class ProfileRequest implements RequestPayloadInterface {}
+class ProfileRequest implements RequestPayloadInterface
+{
+}
diff --git a/src/CXml/Model/Request/RequestPayloadInterface.php b/src/CXml/Model/Request/RequestPayloadInterface.php
index 8c6a3db..7709983 100644
--- a/src/CXml/Model/Request/RequestPayloadInterface.php
+++ b/src/CXml/Model/Request/RequestPayloadInterface.php
@@ -4,4 +4,6 @@
 
 use CXml\Model\PayloadInterface;
 
-interface RequestPayloadInterface extends PayloadInterface {}
+interface RequestPayloadInterface extends PayloadInterface
+{
+}
diff --git a/src/CXml/Model/Response/ResponsePayloadInterface.php b/src/CXml/Model/Response/ResponsePayloadInterface.php
index 2c74592..3dfa25c 100644
--- a/src/CXml/Model/Response/ResponsePayloadInterface.php
+++ b/src/CXml/Model/Response/ResponsePayloadInterface.php
@@ -4,4 +4,6 @@
 
 use CXml\Model\PayloadInterface;
 
-interface ResponsePayloadInterface extends PayloadInterface {}
+interface ResponsePayloadInterface extends PayloadInterface
+{
+}
diff --git a/src/CXml/Model/Response/StatusResponse.php b/src/CXml/Model/Response/StatusResponse.php
index 297022f..eab11c8 100644
--- a/src/CXml/Model/Response/StatusResponse.php
+++ b/src/CXml/Model/Response/StatusResponse.php
@@ -2,4 +2,6 @@
 
 namespace CXml\Model\Response;
 
-class StatusResponse implements ResponsePayloadInterface {}
+class StatusResponse implements ResponsePayloadInterface
+{
+}
diff --git a/tests/CXmlTest/Model/OrderRequestTest.php b/tests/CXmlTest/Model/OrderRequestTest.php
index cb197cb..e87b6e7 100644
--- a/tests/CXmlTest/Model/OrderRequestTest.php
+++ b/tests/CXmlTest/Model/OrderRequestTest.php
@@ -32,13 +32,12 @@
  */
 class OrderRequestTest extends TestCase implements PayloadIdentityFactoryInterface
 {
+    private DtdValidator $dtdValidator;
 
-	private DtdValidator $dtdValidator;
-
-	protected function setUp(): void
-	{
-		$this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
-	}
+    protected function setUp(): void
+    {
+        $this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
+    }
 
     public function testMinimumExample(): void
     {
@@ -101,8 +100,7 @@ public function testMinimumExample(): void
                 8500
             )
         );
-		$orderRequestHeader->addComment(new Comment(null, null, null, 'delivery-note.pdf'));
-
+        $orderRequestHeader->addComment(new Comment(null, null, null, 'delivery-note.pdf'));
 
         $orderRequest = OrderRequest::create(
             $orderRequestHeader
@@ -159,7 +157,7 @@ public function testMinimumExample(): void
         $xml = Serializer::create()->serialize($cxml);
         $this->assertXmlStringEqualsXmlFile('tests/metadata/cxml/samples/OrderRequest.xml', $xml);
 
-		$this->dtdValidator->validateAgainstDtd($xml);
+        $this->dtdValidator->validateAgainstDtd($xml);
     }
 
     public function newPayloadIdentity(): PayloadIdentity
diff --git a/tests/CXmlTest/Model/ProductActivityMessageTest.php b/tests/CXmlTest/Model/ProductActivityMessageTest.php
index 2634b0d..5c77a7d 100644
--- a/tests/CXmlTest/Model/ProductActivityMessageTest.php
+++ b/tests/CXmlTest/Model/ProductActivityMessageTest.php
@@ -23,13 +23,12 @@
  */
 class ProductActivityMessageTest extends TestCase implements PayloadIdentityFactoryInterface
 {
+    private DtdValidator $dtdValidator;
 
-	private DtdValidator $dtdValidator;
-
-	protected function setUp(): void
-	{
-		$this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
-	}
+    protected function setUp(): void
+    {
+        $this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
+    }
 
     public function testMinimumExample(): void
     {
@@ -73,8 +72,8 @@ public function testMinimumExample(): void
         $xml = Serializer::create()->serialize($cxml);
         $this->assertXmlStringEqualsXmlFile('tests/metadata/cxml/samples/ProductActivityMessage.xml', $xml);
 
-		$this->dtdValidator->validateAgainstDtd($xml);
-	}
+        $this->dtdValidator->validateAgainstDtd($xml);
+    }
 
     public function newPayloadIdentity(): PayloadIdentity
     {
diff --git a/tests/CXmlTest/Model/PunchOutSetupRequestTest.php b/tests/CXmlTest/Model/PunchOutSetupRequestTest.php
index 6ef9206..17bd209 100644
--- a/tests/CXmlTest/Model/PunchOutSetupRequestTest.php
+++ b/tests/CXmlTest/Model/PunchOutSetupRequestTest.php
@@ -132,7 +132,7 @@ public function testMinimumExample(): void
         $this->dtdValidator->validateAgainstDtd($xml);
 
         $this->assertXmlStringEqualsXmlFile(__DIR__.'/../../metadata/cxml/samples/PunchOutSetupRequest.xml', $xml);
-	}
+    }
 
     public function newPayloadIdentity(): PayloadIdentity
     {
diff --git a/tests/CXmlTest/Model/QuoteMessageTest.php b/tests/CXmlTest/Model/QuoteMessageTest.php
index 5f74ab6..7a4ade6 100644
--- a/tests/CXmlTest/Model/QuoteMessageTest.php
+++ b/tests/CXmlTest/Model/QuoteMessageTest.php
@@ -7,11 +7,6 @@
 use CXml\Model\Contact;
 use CXml\Model\Country;
 use CXml\Model\Credential;
-use CXml\Model\Inventory;
-use CXml\Model\InventoryQuantity;
-use CXml\Model\ItemId;
-use CXml\Model\Message\ProductActivityDetail;
-use CXml\Model\Message\ProductActivityMessage;
 use CXml\Model\Message\QuoteMessage;
 use CXml\Model\Message\QuoteMessageHeader;
 use CXml\Model\MoneyWrapper;
@@ -23,7 +18,6 @@
 use CXml\Payload\PayloadIdentityFactoryInterface;
 use CXml\Serializer;
 use CXml\Validation\DtdValidator;
-use PhpParser\Node\Expr\AssignOp\Mul;
 use PHPUnit\Framework\TestCase;
 
 /**
@@ -32,13 +26,12 @@
  */
 class QuoteMessageTest extends TestCase implements PayloadIdentityFactoryInterface
 {
+    private DtdValidator $dtdValidator;
 
-	private DtdValidator $dtdValidator;
-
-	protected function setUp(): void
-	{
-		$this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
-	}
+    protected function setUp(): void
+    {
+        $this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
+    }
 
     public function testMinimumExample(): void
     {
@@ -56,48 +49,50 @@ public function testMinimumExample(): void
             'abracadabra'
         );
 
-		$organizationId = new OrganizationId(
-			new Credential(
-				'domain',
-				'identity'
-			)
-		);
+        $organizationId = new OrganizationId(
+            new Credential(
+                'domain',
+                'identity'
+            )
+        );
 
-		$total = new MoneyWrapper('USD', 10000);
+        $total = new MoneyWrapper('USD', 10000);
 
         $quoteMessage = QuoteMessage::create(
-			$organizationId,
-			$total,
-			QuoteMessageHeader::TYPE_ACCEPT,
-			'quoteId',
-			new \DateTime('2021-01-08T23:00:06-08:00'),
-			'de'
+            $organizationId,
+            $total,
+            QuoteMessageHeader::TYPE_ACCEPT,
+            'quoteId',
+            new \DateTime('2021-01-08T23:00:06-08:00'),
+            'de'
         );
 
-		$contact = Contact::create(new MultilanguageString('Joe Smith'))
-			->addEmail('joe.smith@siemens.com')
-			->addIdReference('GUID', '123456');
-
-		$shipTo = new ShipTo(
-			new Address(
-				new MultilanguageString('Acme Inc.'),
-				new PostalAddress(
-					['Acme Inc.', 'Joe Smith'],
-					['123 Anystreet'],
-					'Sunnyvale',
-					new Country('US', 'United States'),
-					null,
-					'CA',
-					'90489'
-				)
-			)
-		);
-
-		$quoteMessage->getQuoteMessageHeader()
-			->setContact($contact)
-			->setShipTo($shipTo)
-			->addExtrinsicAsKeyValue('expiry_date', '2023-01-08T23:00:06-08:00')
-			->addCommentAsString('This is a comment');
+        $contact = Contact::create(new MultilanguageString('Joe Smith'))
+            ->addEmail('joe.smith@siemens.com')
+            ->addIdReference('GUID', '123456')
+        ;
+
+        $shipTo = new ShipTo(
+            new Address(
+                new MultilanguageString('Acme Inc.'),
+                new PostalAddress(
+                    ['Acme Inc.', 'Joe Smith'],
+                    ['123 Anystreet'],
+                    'Sunnyvale',
+                    new Country('US', 'United States'),
+                    null,
+                    'CA',
+                    '90489'
+                )
+            )
+        );
+
+        $quoteMessage->getQuoteMessageHeader()
+            ->setContact($contact)
+            ->setShipTo($shipTo)
+            ->addExtrinsicAsKeyValue('expiry_date', '2023-01-08T23:00:06-08:00')
+            ->addCommentAsString('This is a comment')
+        ;
 
         $cxml = Builder::create('Supplier’s Super Order Processor', 'en-US', $this)
             ->from($from)
@@ -112,7 +107,7 @@ public function testMinimumExample(): void
         $xml = Serializer::create()->serialize($cxml);
         $this->assertXmlStringEqualsXmlFile('tests/metadata/cxml/samples/QuoteMessage.xml', $xml);
 
-		$this->dtdValidator->validateAgainstDtd($xml);
+        $this->dtdValidator->validateAgainstDtd($xml);
     }
 
     public function newPayloadIdentity(): PayloadIdentity
diff --git a/tests/CXmlTest/Model/SerializerTest.php b/tests/CXmlTest/Model/SerializerTest.php
index d7a7837..ea3e77d 100644
--- a/tests/CXmlTest/Model/SerializerTest.php
+++ b/tests/CXmlTest/Model/SerializerTest.php
@@ -377,8 +377,8 @@ public function testSerializeDateOnly(): void
 			</Request>
 			</cXML>';
 
-	    $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
-	}
+        $this->assertXmlStringEqualsXmlString($expectedXml, $actualXml);
+    }
 
     public function testDeserializeOneRowXml(): void
     {
diff --git a/tests/CXmlTest/Model/ShipNoticeRequestTest.php b/tests/CXmlTest/Model/ShipNoticeRequestTest.php
index 930e2fd..f739361 100644
--- a/tests/CXmlTest/Model/ShipNoticeRequestTest.php
+++ b/tests/CXmlTest/Model/ShipNoticeRequestTest.php
@@ -22,13 +22,12 @@
  */
 class ShipNoticeRequestTest extends TestCase implements PayloadIdentityFactoryInterface
 {
+    private DtdValidator $dtdValidator;
 
-	private DtdValidator $dtdValidator;
-
-	protected function setUp(): void
-	{
-		$this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
-	}
+    protected function setUp(): void
+    {
+        $this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
+    }
 
     public function testMinimumExample(): void
     {
@@ -77,7 +76,7 @@ public function testMinimumExample(): void
         $xml = Serializer::create()->serialize($cxml);
         $this->assertXmlStringEqualsXmlFile('tests/metadata/cxml/samples/ShipNoticeRequest.xml', $xml);
 
-		$this->dtdValidator->validateAgainstDtd($xml);
+        $this->dtdValidator->validateAgainstDtd($xml);
     }
 
     public function newPayloadIdentity(): PayloadIdentity
diff --git a/tests/CXmlTest/Model/StatusUpdateRequestTest.php b/tests/CXmlTest/Model/StatusUpdateRequestTest.php
index 359f13d..d50aa51 100644
--- a/tests/CXmlTest/Model/StatusUpdateRequestTest.php
+++ b/tests/CXmlTest/Model/StatusUpdateRequestTest.php
@@ -18,13 +18,12 @@
  */
 class StatusUpdateRequestTest extends TestCase implements PayloadIdentityFactoryInterface
 {
+    private DtdValidator $dtdValidator;
 
-	private DtdValidator $dtdValidator;
-
-	protected function setUp(): void
-	{
-		$this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
-	}
+    protected function setUp(): void
+    {
+        $this->dtdValidator = new DtdValidator(__DIR__.'/../../metadata/cxml/dtd/1.2.050/');
+    }
 
     public function testMinimumExample(): void
     {
@@ -60,7 +59,7 @@ public function testMinimumExample(): void
         $xml = Serializer::create()->serialize($cxml);
         $this->assertXmlStringEqualsXmlFile('tests/metadata/cxml/samples/StatusUpdateRequest.xml', $xml);
 
-		$this->dtdValidator->validateAgainstDtd($xml);
+        $this->dtdValidator->validateAgainstDtd($xml);
     }
 
     public function newPayloadIdentity(): PayloadIdentity