code: public void
  restore() {
  	if (saved_pos < 0) {
  		throw new IllegalStateException("no previous state");
  	}
  	byteBuffer.position(saved_pos);
  	byteBuffer.limit(saved_end);
  	saved_pos = -1;
  	saved_end = -1;
  }
docs: Restores the input stream to its state before the call to {@link #save}.