code: protected final long createExpiresHeader(final CacheControl cacheControl) {
  		
  		final Calendar expires = new GregorianCalendar(TimeZone.getTimeZone("GMT"));
  		
  		if (cacheControl.maxAge() >= 0) {
  			expires.add(Calendar.SECOND, cacheControl.maxAge());
  		}
  		
  		return expires.getTime().getTime();
  	}
docs: Returns an expires header value generated from the given
  {@link CacheControl} annotation.
  
  @param cacheControl the <code>CacheControl</code> annotation from which to
  create the returned expires header value
  
  @return the expires header value