public boolean logModified(Logger log){
  if (isModified()) {
    log.info(_className + " digest is modified");
    return true;
  }
 else   return false;
}

public boolean logModified ( Logger log ) { if ( isModified ( ) ) { log . info ( _className + " digest is modified" ) ; return true ; } else return false ; }
returns true if the underlying resource has changed .
