is_num_children($ws_bottom_left, 0, 'no containers on the lower left workspace');
is_num_children($ws_bottom_right, 1, 'one container on the lower right workspace');
is_num_children($ws_bottom_left, 0, 'no containers on the lower left workspace');
is_num_children($ws_bottom_right, 1, 'one container on the lower right workspace');