### Question:
Friendships { public List<String> getFriendsList(String person) { if (!friendships.containsKey(person)) { return Collections.emptyList(); } return friendships.get(person); }  void makeFriends(String person1, String person2); List<String> getFriendsList(String person); boolean areFriends(String person1, String person2);  }### Answer:
@Test public void alexDoesNotHaveFriends() { Assert.assertTrue("Alex does not have friends", friendships.getFriendsList("Alex").isEmpty()); }
@Test public void joeHas5Friends() { Assert.assertEquals("Joe has 5 friends", 5, friendships.getFriendsList("Joe").size()); }
@Test public void joeIsFriendWithEveryone() { List<String> friendsOfJoe = Arrays.asList("Audrey", "Peter", "Michael", "Britney", "Paul"); Assert.assertTrue( friendships.getFriendsList("Joe").containsAll(friendsOfJoe) ); }