text: load("set.js");
  var names = new Set();
  names.add("David");
  names.add("Jennifer");
  names.add("Cynthia");
  names.add("Mike");
  names.add("Raymond");
  if (names.add("Mike")) {
     print("Mike added") 
  }
  else {
     print("Can't add Mike, must already be in set");
  }
  print(names.show());
  var removed = "Mike";
  if (names.remove(removed)) {
     print(removed + " removed.");
  }
  else {
     print(removed + " not removed.");
  }
  names.add("Clayton");
  print(names.show());
  removed = "Alisa";
  if (names.remove("Mike")) {
     print(removed + " removed.");
  }
  else {
     print(removed + " not removed.");
  }