invalidateBlockPluginCache example

  public function getTheme() {
    return $this->theme;
  }

  /** * {@inheritdoc} */
  public function postSave(EntityStorageInterface $storage, $update = TRUE) {
    parent::postSave($storage, $update);
    if ($this->isReusable() || (isset($this->original) && $this->original->isReusable())) {
      static::invalidateBlockPluginCache();
    }
  }

  /** * {@inheritdoc} */
  public static function preDelete(EntityStorageInterface $storage, array $entities) {
    parent::preDelete($storage, $entities);

    /** @var \Drupal\block_content\BlockContentInterface $block */
    foreach ($entities as $block) {