code: private boolean isChild(Node cn, Node cn2) {
          if (cn == cn2)
              return false;
  
          Queue<Node> toProcess = new LinkedList<Node>();
          toProcess.addAll(cn.getParents());
  
          while (!toProcess.isEmpty()) {
              Node tcn = toProcess.poll();
              if (tcn.equals(cn2))
                  return true;
              Set<Node> parents = tcn.getParents();
              if (parents != null && !parents.isEmpty())
                  toProcess.addAll(parents);
          }
  
          return false;
      }
docs: Indicates if cn is a child of cn2.
  
  @param cn
  @param cn2
  @return