code: public Observable<VirtualHubInner> createOrUpdateAsync(String resourceGroupName, String virtualHubName, VirtualHubInner virtualHubParameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, virtualHubName, virtualHubParameters).map(new Func1<ServiceResponse<VirtualHubInner>, VirtualHubInner>() {
              @Override
              public VirtualHubInner call(ServiceResponse<VirtualHubInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates a VirtualHub resource if it doesn't exist else updates the existing VirtualHub.
  
  @param resourceGroupName The resource group name of the VirtualHub.
  @param virtualHubName The name of the VirtualHub.
  @param virtualHubParameters Parameters supplied to create or update VirtualHub.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request