code: public Observable<Page<PolicySetDefinitionInner>> listByManagementGroupAsync(final String managementGroupId) {
          return listByManagementGroupWithServiceResponseAsync(managementGroupId)
              .map(new Func1<ServiceResponse<Page<PolicySetDefinitionInner>>, Page<PolicySetDefinitionInner>>() {
                  @Override
                  public Page<PolicySetDefinitionInner> call(ServiceResponse<Page<PolicySetDefinitionInner>> response) {
                      return response.body();
                  }
              });
      }
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.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;PolicySetDefinitionInner&gt; object