Argument declaration and print output

Closes #3395357

src/Twig/DevelDebugLogExtension.php

 <?php
 
+declare(strict_types = 1);
+
 namespace Drupal\devel_debug_log\Twig;
 
 use Drupal\Core\StringTranslation\StringTranslationTrait;
+use Drupal\Core\Template\TwigEnvironment;
 use Twig\Extension\AbstractExtension;
 use Twig\TwigFunction;
 
@@ -24,33 +27,33 @@ class DevelDebugLogExtension extends AbstractExtension {
    * {@inheritdoc}
    */
   public function getFunctions() {
-    return array(
-      new TwigFunction('ddl', array($this, 'ddl'), array(
+    return [
+      new TwigFunction('ddl', [$this, 'ddl'], [
         'needs_environment' => TRUE,
         'needs_context' => TRUE,
-      )),
-    );
+      ]),
+    ];
   }
 
   /**
    * Provides ddl function to Twig templates.
    *
-   * @param Twig_Environment $env
+   * @param \Drupal\Core\Template\TwigEnvironment $env
    *   The twig environment instance.
    * @param array $context
    *   An array of parameters passed to the template.
    */
-  public function ddl(\Twig_Environment $env, array $context) {
-    // Don't do anything unless twig_debug is enabled. This reads from the Twig
+  public function ddl(TwigEnvironment $env, array $context) {
+    // Don't do anything unless twig_debug is enabled. This reads from the Twig.
     if (!$env->isDebug()) {
       return;
     }
 
     if (func_num_args() === 2) {
       // No arguments passed, display full Twig context.
-      $ddl_variables = array();
+      $ddl_variables = [];
       foreach ($context as $key => $value) {
-        if (!$value instanceof \Twig_Template) {
+        if (!$value instanceof TwigEnvironment) {
           $ddl_variables[$key] = $value;
         }
       }