### Question:
PageList { boolean decrementUsage( long pageRef ) { long address = offPageBinding( pageRef ); long value = UnsafeUtil.getLongVolatile( address ); long usage = value & MASK_USAGE_COUNT; if ( usage > 0 ) { long update = value - 1; UnsafeUtil.compareAndSwapLong( null, address, value, update ); } return usage <= 1; } PageList( int pageCount, int cachePageSize, MemoryAllocator memoryAllocator, SwapperSet swappers,
              long victimPageAddress, long bufferAlignment );   PageList( PageList pageList );   }### Answer:
@Test public void usageCounterMustBeZeroByDefault() { assertTrue( pageList.decrementUsage( pageRef ) ); }