text: import { List } from 'immutable';
  
  const myList = List.of(
    1, 3, 1, 2, 3, 4, 1, 5,
    2, 4, 6, 1, 5, 2, 7, 1,
    8, 3, 7, 1, 4, 2, 8, 9
  );
  const myUniqueList = myList
    .toOrderedSet()
    .sort()
    .reverse()
    .toList();
  
  console.log('myList', myList.toJS());
  // -> myList [ 1, 3, 1, 2, 3, 4, 1, 5, 2, 4, 6,
  // ->          1, 5, 2, 7, 1, 8, 3, 7, 1, 4, 2,
  // ->          8, 9 ]
  console.log('myUniqueList', myUniqueList.toJS());
  // -> myUniqueList [ 9, 8, 7, 6, 5,
  // ->                4, 3, 2, 1 ]
  