public void makeGraph(DNode node, GraphNode father)  //the DNode class is dependent on the project I'm working on, not Zest itself.
{
  GraphNode newNode = new GraphNode(graph, SWT.NONE, node.getNodeName();
  if(father!=null)
    new GraphConnection(graph, SWT.NONE, newNode, father);
  /* some actions irrelevant to the matter at hand */
  for(DNode comp: node.children())
    makeGraph(comp, newNode);
}

public void makeGraph(DNode node, GraphNode father)
{
  if(graph.getNodes().contains(node.getNodeName())
    /* the node already exists; just add a connection to it. */
  else
    /* New node; create it, connect to it, call makeGraph() for its children. */

if (graph.getNodes().contains(node))

boolean contains(List<GraphNode> nodes, String name) {
  for (GraphNode graphNode : nodes) {
    if (graphNode.getText().equals(name)) {
      return true;
    }
  }
  return false;
}

if (contains(graph.getNodes(), node.getNodeName()))