export interface MySchema extends Schema<MySchema> {
  default: any;
}

const validator = new Validator<MySchema>();

function addDefaults(instance: any, schema: MySchema): any {
  if (schema.default !== undefined && instance === undefined) {
    return schema.default;
  }
  return instance;
}

function validate(instance: any,  uri: string, extension: RewriteFunction<MySchema>): ValidatorResult<MySchema> {
  return validator.validate(instance, uri, { rewrite: extension });
}

export function createDefaults(instance: any,  uri: string): any {
  let result: ValidatorResult<MySchema> = validate(instance, uri, addDefaults);
  if (!result.valid)
    throw "something went wrong with model creation";
  return result.instance;
}