* shared state without additional synchronization necessary for visibility to later executions of
 * the life cycle methods.
 *
 * <h3>Usage Example</h3>
 *
 * <p>Here is a sketch of a service which crawls a website and uses the scheduling capabilities to
 * rate limit itself.
 *
 * <pre>{@code
 * class CrawlingService extends AbstractScheduledService {
 *   private Set<Uri> visited;
 *   private Queue<Uri> toCrawl;

      createConstant(APPLICATION_TYPE, "vnd.oasis.opendocument.text");

  /**
   * <a href="https://tools.ietf.org/id/draft-ellermann-opensearch-01.html">OpenSearch</a>
   * Description files are XML files that describe how a website can be used as a search engine by
   * consumers (e.g. web browsers).
   *
   * @since 28.2
   */
  public static final MediaType OPENSEARCH_DESCRIPTION_UTF_8 =