text: const INST = new WeakMap();
  
  export default class CollectionLocker {
  
      constructor(inst) {
          if (!(inst instanceof Set)) {
              throw new TypeError("Set expected");
          }
          INST.set(this, inst);
      }
  
      get size() {
          const inst = INST.get(this);
          return inst.size;
      }
      
      has(key) {
          const inst = INST.get(this);
          return inst.has(key);
      }
  
      values() {
          const inst = INST.get(this);
          return inst.values();
      }
  
      [Symbol.iterator]() {
          const inst = INST.get(this);
          return inst[Symbol.iterator]();
      }
  
  }
  