docs: public void marshall(CreateUserRequest createUserRequest, ProtocolMarshaller protocolMarshaller) {
  
          if (createUserRequest == null) {
              throw new SdkClientException("Invalid argument passed to marshall(...)");
          }
  
          try {
              protocolMarshaller.marshall(createUserRequest.getUserName(), USERNAME_BINDING);
              protocolMarshaller.marshall(createUserRequest.getMessageAction(), MESSAGEACTION_BINDING);
              protocolMarshaller.marshall(createUserRequest.getFirstName(), FIRSTNAME_BINDING);
              protocolMarshaller.marshall(createUserRequest.getLastName(), LASTNAME_BINDING);
              protocolMarshaller.marshall(createUserRequest.getAuthenticationType(), AUTHENTICATIONTYPE_BINDING);
          } catch (Exception e) {
              throw new SdkClientException("Unable to marshall request to JSON: " + e.getMessage(), e);
          }
      }