code: public MultipleAddresses.Address getReplyAddress() {
          List<MultipleAddresses.Address> replyTo = extension.getAddressesOfType(MultipleAddresses.Type.replyto);
          return replyTo.isEmpty() ? null : replyTo.get(0);
      }
docs: Returns the address to which all replies are requested to be sent or <tt>null</tt> if
  no specific address was provided. When no specific address was provided then the reply
  can be sent to any or all recipients.
  
  @return the address to which all replies are requested to be sent or <tt>null</tt> if
  no specific address was provided.