code: public static void clearRecentHistory(Context context) {
      SearchHistoryDatabase database = SearchHistoryDatabase.getInstance(context);
      SearchHistoryDatabase.deleteAllData(database);
    }
docs: If the search history is being displayed in the search results section you should provide a
  setting for the user to clear their search history. Calling this method will remove all entries
  from the database.
  
  @param context your application's context
  @since 0.1.0