if (!utils.isString(relations) && !utils.isArray(relations)) {
          throw new IllegalArgumentError(errorPrefix + 'relations: Must be a string or an array!', { actual: typeof relations, expected: 'string' });
        } else if (!utils.isObject(options)) {
          throw new IllegalArgumentError(errorPrefix + 'options: Must be an object!', { actual: typeof options, expected: 'object' });
        }