.put("X_WEBKIT_CSP_REPORT_ONLY", "X-WebKit-CSP-Report-Only")
            .buildOrThrow();
    ImmutableSet<String> uppercaseAcronyms =
        ImmutableSet.of(
            "CDN", "CH", "ID", "DNT", "DNS", "DPR", "ECT", "GPC", "HTTP2", "IP", "MD5", "P3P",
            "RTT", "TE", "UA", "UID", "URL", "WWW", "XSS");

    for (Field field : httpHeadersFields()) {
      assertThat(field.get(null))

   */
  public static final String DOWNLINK = "Downlink";

  /**
   * The HTTP <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ECT">{@code
   * ECT}</a> header field name.
   *
   * @since 31.0
   */
  public static final String ECT = "ECT";

  /**
   * The HTTP <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/RTT">{@code
   * RTT}</a> header field name.
   *