code: public UserInner createOrUpdate(String resourceGroupName, String labAccountName, String labName, String userName, UserInner user) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, labAccountName, labName, userName, user).toBlocking().single().body();
      }
docs: Create or replace an existing User.
  
  @param resourceGroupName The name of the resource group.
  @param labAccountName The name of the lab Account.
  @param labName The name of the lab.
  @param userName The name of the user.
  @param user The User registered to a lab
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the UserInner object if successful.