code: String getPayloadAsString(Message<?> message) {
          if (message.getPayload() instanceof com.consol.citrus.message.Message) {
              return  ((com.consol.citrus.message.Message) message.getPayload()).getPayload(String.class);
          } else {
              return message.getPayload().toString();
          }
      }
docs: Reads message payload as String either from message object directly or from nested Citrus message representation.
  @param message
  @return