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