* @param bool $unset True if flag should be unset, false by default
* @return $this
*/
public function setFlag( $flag, $unset = false ) {
* @param bool $unset True if flag should be unset, false by default
* @return $this
*/
public function setFlag( $flag, $unset = false ) {
* @return int 0 if unset, !=0 if set
*/
public function checkFlag( $flag ) {
* @return int 0 if unset, !=0 if set
*/
public function checkFlag( $flag ) {