code: public Observable<Map<String, String>> getAsync(String resourceGroupName, String clusterName, String configurationName) {
          return getWithServiceResponseAsync(resourceGroupName, clusterName, configurationName).map(new Func1<ServiceResponse<Map<String, String>>, Map<String, String>>() {
              @Override
              public Map<String, String> call(ServiceResponse<Map<String, String>> response) {
                  return response.body();
              }
          });
      }
docs: The configuration object for the specified cluster. This API is not recommended and might be removed in the future. Please consider using List configurations API instead.
  
  @param resourceGroupName The name of the resource group.
  @param clusterName The name of the cluster.
  @param configurationName The name of the cluster configuration.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the Map&lt;String, String&gt; object