@Test
  public void testInvalidate() {
    IntStream.range(0, MAX_ENTRIES + 1).forEach((i) -> region.put(i, "value"));

    region.invalidate(0);
    assertNull(region.get(0));
  }
Tests that once an overflowed entry is {@linkplain Region#invalidate invalidated} its value is
gone.
geode-core/src/integrationTest/java/org/apache/geode/cache30/DiskRegionIntegrationTest.java