Tests > setUp() and tearDown() methods > make compatible with PHPUnit 8.0 (and PHP 7.2+)

tests/Utilities/ComposerTest.php

@@ -84,7 +84,7 @@ class ComposerTest extends BaseTestCase
     /**
      * {@inheritdoc}
      */
-    protected function setUp()
+    protected function setUp(): void
     {
         parent::setUp();