code: public ServiceFuture<ExpressRouteLinkInner> getAsync(String resourceGroupName, String expressRoutePortName, String linkName, final ServiceCallback<ExpressRouteLinkInner> serviceCallback) {
          return ServiceFuture.fromResponse(getWithServiceResponseAsync(resourceGroupName, expressRoutePortName, linkName), serviceCallback);
      }
docs: Retrieves the specified ExpressRouteLink resource.
  
  @param resourceGroupName The name of the resource group.
  @param expressRoutePortName The name of the ExpressRoutePort resource.
  @param linkName The name of the ExpressRouteLink resource.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object