*
     * @param factory The URL stream handler factory.
     */
    public static void setURLStreamHandlerFactory(final URLStreamHandlerFactory factory) {
        synchronized (PROTOCOL_HANDLERS) {
            if (Handler.factory != null) {
                throw new IllegalStateException("URLStreamHandlerFactory already set.");
            }
            PROTOCOL_HANDLERS.clear();
            Handler.factory = factory;
        }
    }

     *            The URL stream handler factory.
     */
    public static void setURLStreamHandlerFactory(final URLStreamHandlerFactory factory) {
        synchronized (PROTOCOL_HANDLERS) {
            if (Handler.factory != null) {
                throw new IllegalStateException("URLStreamHandlerFactory already set.");
            }
            PROTOCOL_HANDLERS.clear();
            Handler.factory = factory;
        }
    }

   the way the hostname verifier was selected.
 * Fix: Locking bug in SpdyConnection.
 * Fix: Ignore null header values (for compatibility with HttpURLConnection).
 * Add URLStreamHandlerFactory support so that `URL.openConnection()` uses
   OkHttp.
 * Expose the transport ("http/1.1", "spdy/3", etc.) via magic request headers.
   Use `X-Android-Transports` to write the preferred transports and