@Test
  public void testContainsValue() {
    CustomEntryConcurrentHashMap map = map5();
    assertTrue(map.containsValue("A"));
    assertFalse(map.containsValue("Z"));
  }
containsValue returns true for held values
geode-core/src/integrationTest/java/org/apache/geode/internal/util/concurrent/cm/ConcurrentHashMapJUnitTest.java