@Before
  public void setUp() throws Exception {
    System.setProperty(GeodeGlossary.GEMFIRE_PREFIX + "validateOffHeapWithFill", "true");
    slab = new SlabImpl(SLAB_SIZE);
    allocator = MemoryAllocatorImpl.createForUnitTest(new NullOutOfOffHeapMemoryListener(),
        new NullOffHeapMemoryStats(), new SlabImpl[] {slab});
  }
Enables fill validation and creates the test victim.
geode-core/src/integrationTest/java/org/apache/geode/internal/offheap/MemoryAllocatorFillPatternIntegrationTest.java