return iterator.hasNext();
      }

      @Override
      public Entry<K, V> next() {
        entry = iterator.next();
        return new BiMapEntry(entry);
      }

      @Override
      public void remove() {
        if (entry == null) {
          throw new IllegalStateException("no calls to next() since the last call to remove()");
        }
        V value = entry.getValue();

        return iterator.hasNext();
      }

      @Override
      public Entry<K, V> next() {
        entry = iterator.next();
        return new BiMapEntry(entry);
      }

      @Override
      public void remove() {
        if (entry == null) {
          throw new IllegalStateException("no calls to next() since the last call to remove()");
        }
        V value = entry.getValue();