code: public static MultipleRecipientInfo getMultipleRecipientInfo(Stanza packet) {
          MultipleAddresses extension = packet.getExtension(MultipleAddresses.ELEMENT, MultipleAddresses.NAMESPACE);
          return extension == null ? null : new MultipleRecipientInfo(extension);
      }
docs: Returns the {@link MultipleRecipientInfo} contained in the specified stanza or
  <tt>null</tt> if none was found. Only packets sent to multiple recipients will
  contain such information.
  
  @param packet the stanza to check.
  @return the MultipleRecipientInfo contained in the specified stanza or <tt>null</tt>
  if none was found.