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