Dojo Singleton或至少是静态方法/变量？

require([
  "dojo/_base/declare",
  "dojo/_base/lang"
], function(declare, lang) {
  var Singleton = declare(null, {
    instance: null,
    
    constructor: function() {
      // 初始化操作
    },
    
    getInstance: function() {
      if (!this.instance) {
        this.instance = new Singleton();
      }
      return this.instance;
    }
  });
  
  // 将Singleton转换为单例模式
  lang.mixin(Singleton, {
    instance: null,
    
    getInstance: function() {
      if (!this.instance) {
        this.instance = new Singleton();
      }
      return this.instance;
    }
  });
  
  // 使用单例模式创建实例
  var instance1 = Singleton.getInstance();
  var instance2 = Singleton.getInstance();
  
  console.log(instance1 === instance2);  // true，两个实例是同一个对象
});