code: public Observable<Void> updateAsync(String resourceGroupName, String clusterName, String configurationName, Map<String, String> parameters) {
          return updateWithServiceResponseAsync(resourceGroupName, clusterName, configurationName, parameters).map(new Func1<ServiceResponse<Void>, Void>() {
              @Override
              public Void call(ServiceResponse<Void> response) {
                  return response.body();
              }
          });
      }
docs: Configures the HTTP settings on the specified cluster. This API is deprecated, please use UpdateGatewaySettings in cluster endpoint instead.
  
  @param resourceGroupName The name of the resource group.
  @param clusterName The name of the cluster.
  @param configurationName The name of the cluster configuration.
  @param parameters The cluster configurations.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable for the request