code: String
  rrToString() {
  	StringBuffer sb = new StringBuffer();
  	sb.append(next);
  	int length = bitmap.length();
  	for (short i = 0; i < length; i++)
  		if (bitmap.get(i)) {
  			sb.append(" ");
  			sb.append(Type.string(i));
  		}
  	return sb.toString();
  }
docs: Converts rdata to a String