Remove access to underlying containers inside Graph and Node.

src/main/org/insa/graphics/MainWindow.java

@@ -602,8 +602,8 @@ public class MainWindow extends JFrame {
                     // name that are right-to-left (e.g. arabic names).
                     info += " - " + graph.getMapName() + "\u200e";
                 }
-                info += ", " + graph.getNodes().size() + " nodes, "
-                        + graph.getGraphInformation().getArcCount() + " arcs.";
+                info += ", " + graph.size() + " nodes, " + graph.getGraphInformation().getArcCount()
+                        + " arcs.";
                 graphInfoPanel.setText(info);
 
                 drawGraph();

src/main/org/insa/graphics/NodesInputPanel.java

@@ -65,7 +65,7 @@ public class NodesInputPanel extends JPanel
         public Node findClosestNode(Point point) {
             Node minNode = null;
             double minDis = Double.POSITIVE_INFINITY;
-            for (Node node: graph.getNodes()) {
+            for (Node node: graph) {
                 double dlon = point.getLongitude() - node.getPoint().getLongitude();
                 double dlat = point.getLatitude() - node.getPoint().getLatitude();
                 double dis = dlon * dlon + dlat * dlat; // No need to square
@@ -308,7 +308,7 @@ public class NodesInputPanel extends JPanel
      */
     protected Node getNodeForInput(JTextField textfield) {
         try {
-            Node node = graph.getNodes().get(Integer.valueOf(textfield.getText().trim()));
+            Node node = graph.get(Integer.valueOf(textfield.getText().trim()));
             return node;
         }
         catch (IllegalArgumentException | IndexOutOfBoundsException ex) {

src/main/org/insa/graphics/drawing/components/BasicDrawing.java

@@ -614,7 +614,7 @@ public class BasicDrawing extends JPanel implements Drawing {
 
     @Override
     public void drawGraph(Graph graph, GraphPalette palette) {
-        int repaintModulo = Math.max(1, graph.getNodes().size() / 100);
+        int repaintModulo = Math.max(1, graph.size() / 100);
 
         // Initialize the buffered image
 
@@ -625,8 +625,8 @@ public class BasicDrawing extends JPanel implements Drawing {
         this.removeMouseMotionListener(zoomAndPanListener);
         this.removeMouseWheelListener(zoomAndPanListener);
 
-        for (Node node: graph.getNodes()) {
-            for (Arc arc: node.getSuccessors()) {
+        for (Node node: graph) {
+            for (Arc arc: node) {
                 // Draw arcs only if there are one-way arcs or if origin is lower than
                 // destination, avoid drawing two-ways arc twice.
                 if (arc.getRoadInformation().isOneWay()