473     private static final Unsafe unsafe = Unsafe.getUnsafe();

   473     private void setMap(ConcurrentNavigableMap<E,Object> map) {

   474         UNSAFE.putObjectVolatile(this, mapOffset, map);

   475     }

   476 

   477     private static final sun.misc.Unsafe UNSAFE;

   477             mapOffset = unsafe.objectFieldOffset

   481             UNSAFE = sun.misc.Unsafe.getUnsafe();

   478                 (ConcurrentSkipListSet.class.getDeclaredField("m"));

   482             Class k = ConcurrentSkipListSet.class;

   479         } catch (Exception ex) { throw new Error(ex); }

   483             mapOffset = UNSAFE.objectFieldOffset

   480     }

   484                 (k.getDeclaredField("m"));

   481     private void setMap(ConcurrentNavigableMap<E,Object> map) {

   485         } catch (Exception e) {

   482         unsafe.putObjectVolatile(this, mapOffset, map);

   486             throw new Error(e);

   483     }

   487         }

   484 

   488     }