--- /dev/null
+<?php
+
+namespace Drupal\block_test\Plugin\Block;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Block\BlockBase;
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\State\StateInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides a block to test access.
+ *
+ * @Block(
+ * id = "test_access",
+ * admin_label = @Translation("Test block access")
+ * )
+ */
+class TestAccessBlock extends BlockBase implements ContainerFactoryPluginInterface {
+
+ /**
+ * Tests the test access block.
+ *
+ *
+ * @param array $configuration
+ * The plugin configuration, i.e. an array with configuration values keyed
+ * by configuration option name. The special key 'context' may be used to
+ * initialize the defined contexts by setting it to an array of context
+ * values keyed by context names.
+ * @param string $plugin_id
+ * The plugin_id for the plugin instance.
+ * @param mixed $plugin_definition
+ * The plugin implementation definition.
+ * @param \Drupal\Core\State\StateInterface $state
+ * The state.
+ */
+ public function __construct(array $configuration, $plugin_id, $plugin_definition, StateInterface $state) {
+ parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+ $this->state = $state;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+ return new static(
+ $configuration,
+ $plugin_id,
+ $plugin_definition,
+ $container->get('state')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function blockAccess(AccountInterface $account) {
+ return $this->state->get('test_block_access', FALSE) ? AccessResult::allowed()->setCacheMaxAge(0) : AccessResult::forbidden()->setCacheMaxAge(0);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function build() {
+ return ['#markup' => 'Hello test world'];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getCacheMaxAge() {
+ return Cache::PERMANENT;
+ }
+
+}