text: const map = new WeakMap();
  
  console.log('------------ ES6 WeakMap ------------');
  
  const ob1 = { name: 'Gandalf' };
  const ob2 = { name: 'John' };
  const ob3 = { name: 'Tyrion' };
  
  const retrn = map.set(ob1, 'gandalf@email.com');
  console.log(retrn);
  map.set(ob2, 'johnsnow@email.com');
  map.set(ob3, 'tyrion@email.com');
  
  console.log('has(ob1):', map.has(ob1)); // true
  console.log('has(ob2):', map.has(ob2)); // true
  console.log('has(ob3):', map.has(ob3)); // true
  
  console.log('get(ob3):', map.get(ob3)); // tyrion@email.com
  
  console.log('delete(ob2):', map.delete(ob2));
  console.log('has(ob2):', map.has(ob2)); // false
  