// Check home doesn't contain any wall
assertHomeContains(home);
// 11. Redo 8 times
for (int i = 0; i < 6; i++) {
undoManager.redo();
}
// Check plan contains the four wall
assertHomeContains(home, wall1, wall2, wall3, wall4);
// Check the second and the third wall are selected
assertSelectionContains(home, wall2, wall3);