@Override public long get(long key1, long key2) {
        return super.get0(key1, key2);
    }
@Test
    public void testMigrateTo() {
        final SlotAssignmentResult slot = insert(1, 2);
        mem.putLong(slot.address(), 3);
        final HeapMemoryManager mgr2 = new HeapMemoryManager(memMgr);
        hsa.migrateTo(mgr2.getAllocator());
        assertEquals(0, memMgr.getUsedMemory());
        final long newValueAddr = hsa.get(1, 2);
        assertEquals(3, mem.getLong(newValueAddr));
    }