code: public int deleteIds() {
  		int deleted = 0;
  		try {
  			if (contentsIdDao.isTableExists()) {
  				deleted = contentsIdDao.delete(contentsIdDao.deleteBuilder()
  						.prepare());
  			}
  		} catch (SQLException e) {
  			throw new GeoPackageException(
  					"Failed to delete all contents ids. GeoPackage: "
  							+ geoPackage.getName(), e);
  		}
  		return deleted;
  	}
docs: Delete all contents ids
  
  @return deleted contents ids count