@Override
    public void afterIndexLookup(Collection results) {
      super.afterIndexLookup(results);
      indexUsed = true;
    }
TestObject with wrong comareTo() implementation implementation. Which throws NullPointer while
removing mapping from a MapRangeIndex.
geode-core/src/integrationTest/java/org/apache/geode/cache/query/internal/index/MapRangeIndexMaintenanceJUnitTest.java