### Question:
PositionListIndex { public boolean isEmpty() { return size() == 0; } PositionListIndex(List<LongArrayList> clusters);  PositionListIndex(); PositionListIndex intersect(PositionListIndex otherPLI); List<LongArrayList> getClusters(); @Override PositionListIndex clone(); @Override int hashCode(); @Override boolean equals(Object obj); Long2LongOpenHashMap asHashMap(); long size(); boolean isEmpty(); boolean isUnique(); long getRawKeyError();  }### Answer:
@Test public void testConstructor() { PositionListIndex pli = new PositionListIndex(); assertTrue(pli.clusters.isEmpty()); assertTrue(pli.isEmpty()); }