// Pick a random cell and dfs from it
mxGraphHierarchyNode[] unseenNodesArray = new mxGraphHierarchyNode[1];
unseenNodes.toArray(unseenNodesArray);
model.visit(new mxGraphHierarchyModel.CellVisitor()
{
public void visit(mxGraphHierarchyNode parent,
mxGraphHierarchyNode cell,
mxGraphHierarchyEdge connectingEdge, int layer, int seen)
{