Issue #3492430 by nickdickinsonwilde, akulsaxena: Nullable types must be explicit

src/Exception/PluginNotFoundException.php

@@ -18,7 +18,7 @@ class PluginNotFoundException extends CorePluginNotFoundException {
   /**
    * @inheritDoc
    */
-  public function __construct($plugin_id, $message = '', $code = 0, \Exception $previous = NULL) {
+  public function __construct($plugin_id, $message = '', $code = 0, ?\Exception $previous = NULL) {
     parent::__construct($plugin_id, $message, $code, $previous);
     $this->pluginId = $plugin_id;
   }

src/Form/ImageAPIOptimizeDefaultPipelineConfigForm.php

@@ -28,7 +28,7 @@ class ImageAPIOptimizeDefaultPipelineConfigForm extends ConfigFormBase {
   /**
    * {@inheritdoc}
    */
-  public function buildForm(array $form, FormStateInterface $form_state, Request $request = NULL) {
+  public function buildForm(array $form, FormStateInterface $form_state, ?Request $request = NULL) {
     $config = $this->config('imageapi_optimize.settings');
     $form['default_pipeline'] = [
       '#type' => 'select',

src/Form/ImageAPIOptimizeProcessorAddForm.php

@@ -41,7 +41,7 @@ class ImageAPIOptimizeProcessorAddForm extends ImageAPIOptimizeProcessorFormBase
   /**
    * {@inheritdoc}
    */
-  public function buildForm(array $form, FormStateInterface $form_state, ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
+  public function buildForm(array $form, FormStateInterface $form_state, ?ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
     $form = parent::buildForm($form, $form_state, $imageapi_optimize_pipeline, $imageapi_optimize_processor);
 
     $form['#title'] = $this->t('Add %label processor', ['%label' => $this->imageAPIOptimizeProcessor->label()]);

src/Form/ImageAPIOptimizeProcessorDeleteForm.php

@@ -56,7 +56,7 @@ class ImageAPIOptimizeProcessorDeleteForm extends ConfirmFormBase {
   /**
    * {@inheritdoc}
    */
-  public function buildForm(array $form, FormStateInterface $form_state, ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
+  public function buildForm(array $form, FormStateInterface $form_state, ?ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
     $this->imageAPIOptimizePipeline = $imageapi_optimize_pipeline;
     $this->imageAPIOptimizeProcessor = $this->imageAPIOptimizePipeline->getProcessor($imageapi_optimize_processor);
 

src/Form/ImageAPIOptimizeProcessorEditForm.php

@@ -13,7 +13,7 @@ class ImageAPIOptimizeProcessorEditForm extends ImageAPIOptimizeProcessorFormBas
   /**
    * {@inheritdoc}
    */
-  public function buildForm(array $form, FormStateInterface $form_state, ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
+  public function buildForm(array $form, FormStateInterface $form_state, ?ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
     $form = parent::buildForm($form, $form_state, $imageapi_optimize_pipeline, $imageapi_optimize_processor);
 
     $form['#title'] = $this->t('Edit %label processor', ['%label' => $this->imageAPIOptimizeProcessor->label()]);

src/Form/ImageAPIOptimizeProcessorFormBase.php

@@ -49,7 +49,7 @@ abstract class ImageAPIOptimizeProcessorFormBase extends FormBase {
    *
    * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
-  public function buildForm(array $form, FormStateInterface $form_state, ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
+  public function buildForm(array $form, FormStateInterface $form_state, ?ImageAPIOptimizePipelineInterface $imageapi_optimize_pipeline = NULL, $imageapi_optimize_processor = NULL) {
     $this->imageAPIOptimizePipeline = $imageapi_optimize_pipeline;
     try {
       $this->imageAPIOptimizeProcessor = $this->prepareImageAPIOptimizeProcessor($imageapi_optimize_processor);