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

    /**
     * Sets whether there is a previous page available.
     *
     * @param existPrePage true if there is a previous page, false otherwise
     */
    public void setExistPrePage(final boolean existPrePage) {

  return !str;
};


/**
 * @param {?string} str
 * @return {string} Original str, if it is non-null. Otherwise empty string.
 */
Platform.nullToEmpty = function(str) {
  return str || "";
};


/**
 * @param {?string} str
 * @return {string} Original str, if it is non-empty. Otherwise null;
 */
Platform.emptyToNull = function(str) {
  return str || null;

     * @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);

    /**

      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

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

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

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

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

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

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

     */
    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 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) {

     * @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