code: public Observable<IntegrationAccountSessionInner> createOrUpdateAsync(String resourceGroupName, String integrationAccountName, String sessionName, IntegrationAccountSessionInner session) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, integrationAccountName, sessionName, session).map(new Func1<ServiceResponse<IntegrationAccountSessionInner>, IntegrationAccountSessionInner>() {
              @Override
              public IntegrationAccountSessionInner call(ServiceResponse<IntegrationAccountSessionInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates or updates an integration account session.
  
  @param resourceGroupName The resource group name.
  @param integrationAccountName The integration account name.
  @param sessionName The integration account session name.
  @param session The integration account session.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the IntegrationAccountSessionInner object