code: public V get (Object key)
      {
          V result = _delegate.get(key);
  
          if (_tracking) {
              if (result == null) {
                  if (_seenKeys.contains(key)) {
                      // only count a miss if we've seen the key before
                      _misses++;
                  }
              } else {
                  _hits++;
              }
          }
  
          return result;
      }
docs: documentation inherited from interface