*/
private GraphNode[] fillGraphModel(GraphModel graph) {
GraphNode[] nodes = new GraphNode[7];
GraphBuilder builder = graph.getBuilder();
nodes[0] = builder.newNode(new MockElement("Package1"));
nodes[1] = builder.newNode(new MockElement("Package2"));
nodes[2] = builder.newNode(new MockElement("Package3"));
nodes[3] = builder.newNode(new MockElement("DirectoryElement1"));
nodes[4] = builder.newNode(new MockElement("Source1"));
nodes[5] = builder.newNode(new MockElement("DirectoryElement2"));
nodes[6] = builder.newNode(new MockElement("Source2"));
graph.addEdge(MockRelation.DIRECTORY, nodes[0], nodes[1]);
graph.addEdge(MockRelation.DIRECTORY, nodes[1], nodes[2]);
graph.addEdge(MockRelation.CLASSFILE, nodes[2], nodes[3]);
graph.addEdge(MockRelation.CLASS, nodes[3], nodes[4]);