* this {@code TopKSelector}.
   *
   * <p>The returned list is an unmodifiable copy and will not be affected by further changes to
   * this {@code TopKSelector}. This method returns in O(k log k) time.
   */
  public List<T> topK() {
    @SuppressWarnings("nullness") // safe because we pass sort() a range that contains real Ts
    T[] castBuffer = (T[]) buffer;
    sort(castBuffer, 0, bufferSize, comparator);

      if (type instanceof WildcardType) {
        WildcardType wildcardType = (WildcardType) type;
        Type[] lowerBounds = wildcardType.getLowerBounds();
        if (lowerBounds.length == 0) { // ? extends something changes to capture-of
          return captureAsTypeVariable(wildcardType.getUpperBounds());
        } else {
          // TODO(benyu): handle ? super T somehow.
          return type;
        }
      }

2. **Create** your feature branch: `git checkout -b feature/amazing-feature`
3. **Follow** the coding standards: `mvn formatter:format`
4. **Add** comprehensive tests for new functionality
5. **Commit** your changes: `git commit -m 'Add amazing feature'`
6. **Push** to the branch: `git push origin feature/amazing-feature`
7. **Submit** a Pull Request with detailed description

### Code Standards

      if (type instanceof WildcardType) {
        WildcardType wildcardType = (WildcardType) type;
        Type[] lowerBounds = wildcardType.getLowerBounds();
        if (lowerBounds.length == 0) { // ? extends something changes to capture-of
          return captureAsTypeVariable(wildcardType.getUpperBounds());
        } else {
          // TODO(benyu): handle ? super T somehow.
          return type;
        }
      }

            throw new SearchEngineClientException("[" + index + "] Failed to set " + value + " to " + field + " for doc " + id, e);
        }
    }

    /**
     * Refreshes the specified indices to make recent changes visible for search.
     *
     * @param indices the indices to refresh
     */
    public void refresh(final String... indices) {