planController.setMode(PlanController.Mode.SELECTION);
// Check current mode is SELECTION
assertEquals("Current mode isn't " + PlanController.Mode.SELECTION,
PlanController.Mode.SELECTION, planController.getMode());
// Press the delete key
planController.deleteSelection();
// Check plan contains only the first three walls
assertHomeContains(home, wall1, wall2, wall3);
// 5. Use WALL_CREATION mode
planController.setMode(PlanController.Mode.WALL_CREATION);