code: public CreateWaterMarkResponse createWaterMark(CreateWaterMarkRequest request) {
          checkStringNotEmpty(request.getBucket(), "The parameter bucket should NOT be null or empty string.");
          checkStringNotEmpty(request.getKey(), "The parameter key should NOT be null or empty string.");
          InternalRequest internalRequest = createRequest(HttpMethodName.POST, request, WATER_MARK);
          
          return invokeHttpClient(internalRequest, CreateWaterMarkResponse.class);
      }
docs: Creates a water mark and return water mark ID
  
  @param request The request object containing all options for creating new water mark.
  
  @return watermarkId the unique ID of the new water mark.