code: public V put (K key, V value)
      {
          V result = _delegate.put(key, value);
  
          if (_tracking) {
              _seenKeys.add(key);
          }
  
          // avoid fruitless NOOPs
          if (result != value) {
              // updated our computed "size"
              _size += _sizer.computeSize(value);
              entryRemoved(result);
  //         System.out.println("Added " + value + ": " + _size);
          }
  
          // flush if needed
          flush();
  
          return result;
      }
docs: documentation inherited from interface