code: public ServiceFuture<VirtualNetworkInner> createOrUpdateAsync(String resourceGroupName, String virtualNetworkName, VirtualNetworkInner parameters, final ServiceCallback<VirtualNetworkInner> serviceCallback) {
          return ServiceFuture.fromResponse(createOrUpdateWithServiceResponseAsync(resourceGroupName, virtualNetworkName, parameters), serviceCallback);
      }
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
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object