code: function createKoyomi(obj) {
    return Object.create(koyomi,{
      _startMonth: {
        value: obj ? obj._startMonth : CONFIG.START_MONTH,
        writable: true, enumerable: false, configurable: false
      },
      _startWeek: {
        value: obj ? obj._startWeek : getWeekIndex(CONFIG.START_WEEK),
        writable: true, enumerable: false, configurable: false
      },
      _defaultFormat:{
        value: obj ? obj._defaultFormat : compileFormat(CONFIG.FORMAT),
        writable: true, enumerable: false, configurable: false
      },
      _regularHoliday:{
        value: obj ? obj._regularHoliday : compileRegularHoliday(CONFIG.REGULAR_HOLIDAY),
        writable: true, enumerable: false, configurable: false
      },
      _seasonHoliday:{
        value: obj ? obj._seasonHoliday : compileSeasonHoliday(CONFIG.SEASON_HOLIDAY),
        writable: true, enumerable: false, configurable: false
      },
      _openOnHoliday: {
        value: obj ? obj._openOnHoliday : CONFIG.OPEN_ON_HOLIDAY,
        writable: true, enumerable: false, configurable: false
      },
      dayInfo: {
        value: obj ? JSON.parse(JSON.stringify(obj.dayInfo)) :{},
        writable: true, enumerable: false, configurable: false
      },
      bizCache: {
        value: obj ? JSON.parse(JSON.stringify(obj.bizCache)) : {},
        writable: true, enumerable: false, configurable: false
      }
    });
  }
docs: ********* createObject **********