private void iterate() {
    Iterator itr = list.iterator();
    int i = 1;
    while (itr.hasNext()) {
      assertEquals(i++, itr.next());
    }
  }
This tests concurrent modification of IndexElemArray and to make sure elementData and size are
updated atomically. Ticket# GEODE-106.
geode-core/src/test/java/org/apache/geode/cache/query/internal/index/IndexElemArrayJUnitTest.java