docs: public Observable<DatabasePrincipalListResultInner> addPrincipalsAsync(String resourceGroupName, String clusterName, String databaseName, List<DatabasePrincipalInner> value) {
          return addPrincipalsWithServiceResponseAsync(resourceGroupName, clusterName, databaseName, value).map(new Func1<ServiceResponse<DatabasePrincipalListResultInner>, DatabasePrincipalListResultInner>() {
              @Override
              public DatabasePrincipalListResultInner call(ServiceResponse<DatabasePrincipalListResultInner> response) {
                  return response.body();
              }
          });
      }