docs: private void processElementGamma(GeneratorSingleCluster cluster, Node cur) {
      double k = 1.0;
      double theta = 1.0;
      String kstr = ((Element) cur).getAttribute(ATTR_K);
      if(kstr != null && kstr.length() > 0) {
        k = ParseUtil.parseDouble(kstr);
      }
      String thetastr = ((Element) cur).getAttribute(ATTR_THETA);
      if(thetastr != null && thetastr.length() > 0) {
        theta = ParseUtil.parseDouble(thetastr);
      }
  
      // *** New normal distribution generator
      Random random = cluster.getNewRandomGenerator();
      Distribution generator = new GammaDistribution(k, theta, random);
      cluster.addGenerator(generator);
  
      // 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());
        }
      }
    }