### Question:
RemoveContactUpdate extends Update { @Override public void applyUpdate(RepositorySet repositorySet) { repositorySet.userRepository.setIsFriend(creator, false); } RemoveContactUpdate(@JsonProperty("time-created") Date timeCreated,
                               @JsonProperty("creator") int creator); @Override void applyUpdate(RepositorySet repositorySet);  }### Answer:
@Test public void applyUpdate() throws Exception { RemoveContactUpdate update = new RemoveContactUpdate(date, creator1); update.applyUpdate(mockRepos); verify(mockUserRepository).setIsFriend(creator1, false); }