### Question:
SeRequestSet implements Serializable { public SeRequest getSingleRequest() { if (sortedRequests.size() != 1) { throw new IllegalStateException("This method only support ONE element"); } return sortedRequests.iterator().next(); } SeRequestSet(Set<SeRequest> seRequests);  SeRequestSet(SeRequest seRequest); void add(SeRequest seRequest); Set<SeRequest> getRequests(); SeRequest getSingleRequest(); @Override String toString();  }### Answer:
@Test public void getSingleRequest() { seRequestSet = new SeRequestSet(firstRequest); assertEquals(firstRequest, seRequestSet.getSingleRequest()); }