/**
  * 설치하고 일주일 지나면 광고표시
  *
  * @return
  */
 public boolean isPurchaseInApp() {
   return tinyDb.getBoolean(IN_APP_BILLING_AD_DELETE);
 }
 public int getCurrentWordBookId() {
   return tinyDb.getInt(STATE_WORD_BOOK_ID);
 }
 public void saveInAppAddDelete() {
   tinyDb.putBoolean(IN_APP_BILLING_AD_DELETE, true);
 }
 public int getCurrentWordPosition() {
   return tinyDb.getInt(STATE_WORD_POSITION);
 }
 public void saveCurrentWordBookId(int id) {
   tinyDb.putInt(STATE_WORD_BOOK_ID, id);
 }
 public List<Word> getWordList() {
   return gson.fromJson(
       tinyDb.getString(STATE_WORD_LIST), new TypeToken<List<Word>>() {}.getType());
 }
 public void saveCurrentWordPosition(int position) {
   tinyDb.putInt(STATE_WORD_POSITION, position);
 }
 public boolean getExamViewVisibilty() {
   return tinyDb.getBoolean(STATE_EXAM_VIEW_VISIBILITY);
 }
 public void saveWordList(List<Word> list) {
   String json = gson.toJson(list);
   tinyDb.putString(STATE_WORD_LIST, json);
 }
 public void saveExamViewVisibility(boolean isVisible) {
   tinyDb.putBoolean(STATE_EXAM_VIEW_VISIBILITY, isVisible);
 }
 public boolean getMeanViewVisibilty() {
   return tinyDb.getBoolean(STATE_MEAN_VIEW_VISIBILITY);
 }
 public void saveMeanViewVisibility(boolean isVisible) {
   tinyDb.putBoolean(STATE_MEAN_VIEW_VISIBILITY, isVisible);
 }
 public boolean getWordViewVisibilty() {
   return tinyDb.getBoolean(STATE_WORD_VIEW_VISIBILITY);
 }
 public void saveWordViewVisibility(boolean isVisible) {
   tinyDb.putBoolean(STATE_WORD_VIEW_VISIBILITY, isVisible);
 }