code: public static boolean isSuccess(ModelNode operationResult) {
          if (operationResult != null) {
              return operationResult.hasDefined(OUTCOME)
                  && operationResult.get(OUTCOME).asString().equals(OUTCOME_SUCCESS);
          }
          return false;
      }
docs: Returns <code>true</code> if the operation was a success; <code>false</code> otherwise.
  
  @param operationResult the operation result to test
  @return the success or failure flag of the result