public boolean isCrc(){
  return isFlags(FLAG_CACHED_VALUES_CHECKED & FLAG_CRC_CALCED);
}

public boolean isCrc ( ) { return isFlags ( FLAG_CACHED_VALUES_CHECKED & FLAG_CRC_CALCED ) ; }
find out if privatecrc value known ( and not simply cached ) . can be used to find out if the privatecrc can be retrieved via getcrc ( ) without forcing it be calculated
