code: public ServiceFuture<List<PolicySetDefinitionInner>> listByManagementGroupAsync(final String managementGroupId, final ListOperationCallback<PolicySetDefinitionInner> serviceCallback) {
          return AzureServiceFuture.fromPageResponse(
              listByManagementGroupSinglePageAsync(managementGroupId),
              new Func1<String, Observable<ServiceResponse<Page<PolicySetDefinitionInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<PolicySetDefinitionInner>>> call(String nextPageLink) {
                      return listByManagementGroupNextSinglePageAsync(nextPageLink);
                  }
              },
              serviceCallback);
      }
docs: Retrieves all policy set definitions in management group.
  This operation retrieves a list of all the a policy set definition in the given management group.
  
  @param managementGroupId The ID of the management group.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object