Fatal error: Declaration of::setUp() must be compatible with...

Fatal error: Declaration of::setUp() must be compatible with PHPUnit\Framework\TestCase::setUp(): void

Test/Unit/Comment/ApiKeyEndingTest.php

@@ -14,7 +14,7 @@ class ApiKeyEndingTest extends TestCase
      */
     private $apiKeyEndingComment;
 
-    public function setUp()
+    public function setUp(): void
     {
         /** @var MockObject|Encryptor $encryptor */
         $encryptor = $this->createMock(Encryptor::class);

Test/Unit/Helper/DataTest.php

@@ -37,7 +37,7 @@ class DataTest extends \PHPUnit\Framework\TestCase
             ->getMock();
     }
 
-    public function setUp()
+    public function setUp(): void
     {
         $context = $this->getSimpleMock(\Magento\Framework\App\Helper\Context::class);
         $encryptor = $this->getSimpleMock(\Magento\Framework\Encryption\EncryptorInterface::class);

Test/Unit/Helper/IpAddressTest.php

@@ -37,7 +37,7 @@ class IpAddressTest extends \PHPUnit\Framework\TestCase
             ->getMock();
     }
 
-    protected function setUp()
+    protected function setUp(): void
     {
         $cache = $this->getSimpleMock(\Magento\Framework\App\CacheInterface::class);
         $cache->method('load')->willReturn(

Test/Unit/Model/AdyenInitiateTerminalApiTest.php

@@ -43,7 +43,7 @@ class AdyenInitiateTerminalApiTest extends \PHPUnit\Framework\TestCase
             ->getMock();
     }
 
-    public function setUp()
+    public function setUp(): void
     {
         $adyenHelper = $this->getSimpleMock(\Adyen\Payment\Helper\Data::class);
         $adyenLogger = $this->getSimpleMock(\Adyen\Payment\Logger\AdyenLogger::class);

Test/Unit/Model/AdyenOriginKeyTest.php

@@ -33,7 +33,7 @@ class AdyenOriginKeyTest extends TestCase
     /** @var AdyenHelper|MockObject */
     private $helper;
 
-    protected function setUp()
+    protected function setUp(): void
     {
         $this->helper = $this->getMockBuilder(AdyenHelper::class)
             ->disableOriginalConstructor()

Test/Unit/Ui/Component/Listing/Column/NotificationColumnTest.php

@@ -66,7 +66,7 @@ class NotificationColumnTest extends TestCase
      */
     private $notificationColumn;
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->orderMock = $this->getMockBuilder(Order::class)
             ->disableOriginalConstructor()