code: public Observable<VirtualNetworkInner> createOrUpdateAsync(String resourceGroupName, String virtualNetworkName, VirtualNetworkInner parameters) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, virtualNetworkName, parameters).map(new Func1<ServiceResponse<VirtualNetworkInner>, VirtualNetworkInner>() {
              @Override
              public VirtualNetworkInner call(ServiceResponse<VirtualNetworkInner> response) {
                  return response.body();
              }
          });
      }
docs: Creates or updates a virtual network in the specified resource group.
  
  @param resourceGroupName The name of the resource group.
  @param virtualNetworkName The name of the virtual network.
  @param parameters Parameters supplied to the create or update virtual network operation
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request