### Question:
EntryIDSet implements Iterable<EntryID> { static EntryIDSet newUndefinedSet() { return newUndefinedSetWithKey(NO_KEY); } private  EntryIDSet(EntryIDSetImplementor concreteImpl); long size(); void toString(StringBuilder buffer); @Override String toString(); long[] toLongArray(); boolean isDefined(); boolean add(EntryID entryID); boolean remove(EntryID entryID); boolean contains(EntryID entryID); void addAll(EntryIDSet that); void retainAll(EntryIDSet that); void removeAll(EntryIDSet that); @Override Iterator<EntryID> iterator(); Iterator<EntryID> iterator(EntryID begin); static final EntryIDSetCodec CODEC_V1; static final EntryIDSetCodec CODEC_V2; }### Answer:
@Test public void testNewUndefinedSet() { assertThat(newUndefinedSet().isDefined()).isFalse(); assertThat(newUndefinedSetWithKey(KEY).isDefined()).isFalse(); assertThat(newUndefinedSetWithKey(KEY).size()).isEqualTo(Long.MAX_VALUE); }