@Before
public void before() {
TreeNode root = new TreeNodeImpl(null, "root");
TreeNode c1 = new TreeNodeImpl(root, "c1");
TreeNode c2 = new TreeNodeImpl(root, "c2");
TreeNode c3 = new TreeNodeImpl(c1, "c3");
TreeNode c4 = new TreeNodeImpl(c1, "c4");
TreeNode c5 = new TreeNodeImpl(c2, "c5");
TreeNode c6 = new TreeNodeImpl(c2, "c6");
c1.addChild(c4);
c1.addChild(c3);
c2.addChild(c5);
c2.addChild(c6);
root.addChild(c1);
root.addChild(c2);
this.tree = new TreeImpl(root);
}
