code: 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();
              }
          });
      }
docs: Add Database principals permissions.
  
  @param resourceGroupName The name of the resource group containing the Kusto cluster.
  @param clusterName The name of the Kusto cluster.
  @param databaseName The name of the database in the Kusto cluster.
  @param value The list of Kusto database principals.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the DatabasePrincipalListResultInner object