code: public static Date getDelayTimestamp(Stanza packet) {
          DelayInformation delayInformation = getDelayInformation(packet);
          if (delayInformation == null) {
              return null;
          }
          return delayInformation.getStamp();
      }
docs: Get the Delayed Delivery timestamp or <code>null</code>.
  
  @param packet
  @return the Delayed Delivery timestamp or <code>null</code>