docs: public CreateSubnetResponse createSubnet(CreateSubnetRequest request)
              throws BceClientException {
          checkNotNull(request, "request should not be null.");
          if (Strings.isNullOrEmpty(request.getClientToken())) {
              request.setClientToken(this.generateClientToken());
          }
          checkStringNotEmpty(request.getName(), "name should not be empty");
          checkStringNotEmpty(request.getCidr(), "cidr should not be empty");
          checkStringNotEmpty(request.getZoneName(), "zone name should not be empty");
          checkStringNotEmpty(request.getVpcId(), "vpc id should not be empty");
  
          InternalRequest internalRequest = this.createRequest(request, HttpMethodName.POST, SUBNET_PREFIX);
          if (!Strings.isNullOrEmpty(request.getClientToken())) {
              internalRequest.addParameter("clientToken", request.getClientToken());
          }
          fillPayload(internalRequest, request);
          return invokeHttpClient(internalRequest, CreateSubnetResponse.class);
      }