dataset.copyInstances(0, this, dataset.numInstances());
tokenizer = new StreamTokenizer(reader); initTokenizer(tokenizer); readHeader(tokenizer); m_ClassIndex = -1; m_Instances = new FastVector(1000); while (getInstance(tokenizer, true)) {}; compactify();
  public Instances(Instances dataset) {    this(dataset, dataset.numInstances());    dataset.copyInstances(0, this, dataset.numInstances());  }