text: function test() {
  
  var key1 = {};
  var key2 = {};
  var weakmap = new WeakMap([[key1, 123], [key2, 456]]);
  
  return weakmap.has(key1) && weakmap.get(key1) === 123 &&
         weakmap.has(key2) && weakmap.get(key2) === 456;
        
  }
  
  if (!test())
      throw new Error("Test failed");
  
  