Issue #2822975 by tedbow: Clean up unused portions of offcanvas_test module

core/modules/outside_in/tests/modules/offcanvas_test/src/Plugin/Block/TestBlock.php

-<?php
-
-namespace Drupal\offcanvas_test\Plugin\Block;
-
-use Drupal\Core\Block\BlockBase;
-use Drupal\Core\Url;
-
-/**
- * Provides an 'Off-canvas test block' block.
- *
- * @Block(
- *   id = "offcanvas_links_block",
- *   admin_label = @Translation("Off-canvas test block")
- * )
- */
-class TestBlock extends BlockBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function build() {
-    return [
-      'offcanvas_link_1' => [
-        '#title' => $this->t('Click Me 1!'),
-        '#type' => 'link',
-        '#url' => Url::fromRoute('offcanvas_test.thing1'),
-        '#attributes' => [
-          'class' => ['use-ajax'],
-          'data-dialog-type' => 'offcanvas',
-        ],
-      ],
-      'offcanvas_link_2' => [
-        '#title' => $this->t('Click Me 2!'),
-        '#type' => 'link',
-        '#url' => Url::fromRoute('offcanvas_test.thing2'),
-        '#attributes' => [
-          'class' => ['use-ajax'],
-          'data-dialog-type' => 'offcanvas',
-        ],
-      ],
-      '#attached' => [
-        'library' => [
-          'outside_in/drupal.off_canvas',
-        ],
-      ],
-    ];
-  }
-
-}