code: public ServiceFuture<ClusterInner> getByResourceGroupAsync(String resourceGroupName, String clusterName, final ServiceCallback<ClusterInner> serviceCallback) {
          return ServiceFuture.fromResponse(getByResourceGroupWithServiceResponseAsync(resourceGroupName, clusterName), serviceCallback);
      }
docs: Gets the specified cluster.
  
  @param resourceGroupName The name of the resource group.
  @param clusterName The name of the cluster.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object