docs: private void processElementPoint(List<double[]> points, Node cur) {
      double[] point = null;
      String vstr = ((Element) cur).getAttribute(ATTR_VECTOR);
      if(vstr != null && vstr.length() > 0) {
        point = parseVector(vstr);
      }
      if(point == null) {
        throw new AbortException("No translation vector given.");
      }
  
      // *** add new point
      points.add(point);
  
      // TODO: check for unknown attributes.
      XMLNodeIterator iter = new XMLNodeIterator(cur.getFirstChild());
      while(iter.hasNext()) {
        Node child = iter.next();
        if(child.getNodeType() == Node.ELEMENT_NODE) {
          LOG.warning("Unknown element in XML specification file: " + child.getNodeName());
        }
      }
    }