docs: public Observable<VirtualNetworkLinkInner> beginUpdateAsync(String resourceGroupName, String privateZoneName, String virtualNetworkLinkName, VirtualNetworkLinkInner parameters, String ifMatch) {
          return beginUpdateWithServiceResponseAsync(resourceGroupName, privateZoneName, virtualNetworkLinkName, parameters, ifMatch).map(new Func1<ServiceResponse<VirtualNetworkLinkInner>, VirtualNetworkLinkInner>() {
              @Override
              public VirtualNetworkLinkInner call(ServiceResponse<VirtualNetworkLinkInner> response) {
                  return response.body();
              }
          });
      }