Issue #3332313: Declare $testNodes property in HandlePdfControllerTest

tests/src/Functional/HandlePdfControllerTest.php

@@ -18,6 +18,13 @@ use Symfony\Component\HttpFoundation\ResponseHeaderBag;
  */
 class HandlePdfControllerTest extends FillPdfUploadTestBase {
 
+  /**
+   * Array of nodes to run tests with.
+   *
+   * @var array
+   */
+  private $testNodes = [];
+
   /**
    * {@inheritdoc}
    */