.put("SEC_WEBSOCKET_KEY", "Sec-WebSocket-Key")
            .put("SEC_WEBSOCKET_PROTOCOL", "Sec-WebSocket-Protocol")
            .put("SEC_WEBSOCKET_VERSION", "Sec-WebSocket-Version")
            .put("X_WEBKIT_CSP", "X-WebKit-CSP")
            .put("X_WEBKIT_CSP_REPORT_ONLY", "X-WebKit-CSP-Report-Only")
            .buildOrThrow();
    ImmutableSet<String> uppercaseAcronyms =
        ImmutableSet.of(

            .put("SEC_WEBSOCKET_KEY", "Sec-WebSocket-Key")
            .put("SEC_WEBSOCKET_PROTOCOL", "Sec-WebSocket-Protocol")
            .put("SEC_WEBSOCKET_VERSION", "Sec-WebSocket-Version")
            .put("X_WEBKIT_CSP", "X-WebKit-CSP")
            .put("X_WEBKIT_CSP_REPORT_ONLY", "X-WebKit-CSP-Report-Only")
            .buildOrThrow();
    ImmutableSet<String> uppercaseAcronyms =
        ImmutableSet.of(

   * version 25. Please, use {@link #CONTENT_SECURITY_POLICY} to pass the CSP.
   *
   * @since 20.0
   */
  public static final String X_WEBKIT_CSP = "X-WebKit-CSP";
  /**
   * The HTTP nonstandard {@code X-WebKit-CSP-Report-Only} header field name. It was introduced in
   * <a href="https://www.w3.org/TR/2011/WD-CSP-20111129/">CSP v.1</a> and used by the Chrome until