@Test
  public void testReplace2() {
    CustomEntryConcurrentHashMap map = map5();
    assertNotNull(map.replace(one, "Z"));
    assertEquals("Z", map.get(one));
  }
replace succeeds if the key is already present
geode-core/src/integrationTest/java/org/apache/geode/internal/util/concurrent/cm/ConcurrentHashMapJUnitTest.java