* added first.
   */
  @CheckForNull
  private Listener clearListeners(@CheckForNull Listener onto) {
    // We need to
    // 1. atomically swap the listeners with TOMBSTONE, this is because addListener uses that
    //    to synchronize with us
    // 2. reverse the linked list, because despite our rather clear contract, people depend on us

   * fraction {@code sqrt(1/(R*R) - 1)} of the population standard deviation of {@code x}. This fit
   * does not normally minimize that error: to do that, you should swap the roles of {@code x} and
   * {@code y}.
   *
   * <h3>Non-finite values</h3>
   *
   * <p>If the dataset contains any non-finite values ({@link Double#POSITIVE_INFINITY}, {@link

   * Language</a>.
   *
   * @since 13.0
   */
  public static final MediaType WML_UTF_8 = createConstantUtf8(TEXT_TYPE, "vnd.wap.wml");

  /**
   * As described in <a href="http://www.ietf.org/rfc/rfc3023.txt">RFC 3023</a>, this constant
   * ({@code text/xml}) is used for XML documents that are "readable by casual users." {@link