@Override
    public int compareTo(Object o) {
      if (id == ((TestObject) o).id) {
        return 0;
      } else {
        return id > ((TestObject) o).id ? -1 : 1;
      }
    }
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