code: public static DelayInformation getDelayInformation(Stanza packet) {
          DelayInformation delayInformation = getXep203DelayInformation(packet);
          if (delayInformation != null) {
              return delayInformation;
          }
          return getLegacyDelayInformation(packet);
      }
docs: Get Delayed Delivery information. This method first looks for a PacketExtension with the
  XEP-203 namespace and falls back to the XEP-91 namespace.
  
  @param packet
  @return the Delayed Delivery information or <code>null</code>