text: // SETS
  const list = new Set();
  list.add('Rich');
  list.add('Bob');
  list.add('Doug');
  list.add('Rich');
  
  console.log(list.has('Doug'));
  console.log(list);
  console.log(list);
  
  const line = list.values();
  console.log(line.next().value);
  console.log(line);
  list.add('Mom');
  console.log(line);
  console.log(line.next().value);
  console.log(line.next().value);
  console.log(line.next().value);
  console.log(line.next().done);
  