* @return true if the thumbnail was successfully generated, false otherwise
     */
    boolean generate(String thumbnailId, File outputFile);

    /**
     * Checks if this generator can handle the given document.
     * @param docMap The document map containing metadata.
     * @return True if this generator can handle the document, false otherwise.
     */
    boolean isTarget(Map<String, Object> docMap);

    /**

     */
    Class<?> getElementClassOfCollection(int index);

    /**
     * Returns the key type if the parameter type of the method is a parameterized {@link Map}.
     *
     * @param index
     *            The index of the parameter
     * @return The key type if the parameter type is a parameterized {@link Map}, otherwise {@literal null}
     */

     * @return This builder instance.
     */
    public SuggestRequestBuilder setMatchWordFirst(final boolean matchWordFirst) {
        request.setMatchWordFirst(matchWordFirst);
        return this;
    }

    /**
     * Sets whether to skip duplicate words.
     * @param skipDuplicateWords True to skip duplicate words, false otherwise.
     * @return This builder instance.

      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of

      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of

      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of

      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of

     * @param key the parameter key to look up
     * @return the parameter value if found, null otherwise
     */
    public Object get(final String key) {
        return params.get(key);
    }

    /**
     * Retrieves a parameter value as a String.
     * If the stored value is already a String, it is returned directly.
     * Otherwise, the toString() method is called on the value.
     *
     * @param key the parameter key to look up

     *
     * @return true if a previous page exists, false otherwise
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets the flag indicating whether a previous page exists.
     *
     * @param existPrePage true if a previous page exists, false otherwise
     */
    public void setExistPrePage(final boolean existPrePage) {

   * Returns the string if it is not null, or an empty string otherwise.
   *
   * @param string the string to test and possibly return
   * @return {@code string} if it is not null; {@code ""} otherwise
   */
  static String nullToEmpty(@Nullable String string) {
    return (string == null) ? "" : string;
  }

  /**
   * Returns the string if it is not empty, or a null string otherwise.
   *