code: @Override
    public boolean logModified(Logger log)
    {
      if (_depend.logModified(log)) {
        return true;
      }
      else if (_sourcePath == null)
        return false;
        
      else if (_sourcePath.getLastModified() != _sourceLastModified) {
        log.info("source modified time: " + _sourcePath +
                 " old:" + new Date(_sourceLastModified) +
                 " new:" + new Date(_sourcePath.getLastModified()));
  
        return true;
      }
      else if (_sourcePath.length() != _sourceLength) {
        log.info("source modified length: " + _sourcePath +
                 " old:" + _sourceLength +
                 " new:" + _sourcePath.length());
  
        return true;
      }
      else {
        return false;
      }
    }
docs: Returns true if the source file has been modified.