text: class KV {
      constructor(key, value) {
          this.k = Symbol(key);
          this[this.k] = value;
      }
      getKey(){
          return this.k;
      }
      getValue() {
          return this[this.k];
      }
      
  }
  
  var kv = new KV('key','value');
  console.log(kv.getKey());
  console.log(kv.getValue());
  
  
  