@Test
  public void testPutIfAbsent2() {
    CopyOnWriteHashMap map = map5();
    assertEquals("A", map.putIfAbsent(one, "Z"));
  }
putIfAbsent does not add the pair if the key is already present
geode-core/src/integrationTest/java/org/apache/geode/internal/util/concurrent/CopyOnWriteHashMapJUnitTest.java