Validator = function (input, rules, customMessages) {
  var lang = Validator.getDefaultLang();
  this.input = input || {};

  this.messages = Lang._make(lang);
  this.messages._setCustom(customMessages);
  this.setAttributeFormatter(Validator.prototype.attributeFormatter);

  this.errors = new Errors();
  this.errorCount = 0;

  this.hasAsync = false;
  this.rules = this._parseRules(rules);
}
Register implicit async rule

@param  {string}   name
@param  {function} fn
@return {void}