public TSDataOptimizerTask(@NonNull Path destDir){
  this.destDir=destDir;
  if (!Files.isDirectory(destDir))   throw new IllegalArgumentException(destDir + " is not a directory");
}

public TSDataOptimizerTask ( @ NonNull Path destDir ) { this . destDir = destDir ; if ( ! Files . isDirectory ( destDir ) ) throw new IllegalArgumentException ( destDir + " is not a directory" ) ; }
create a new optimizer task and fill it with the given files .
