public List<String[]> select() {
		return select(this.datas.length);
	}
@Test
	public void selectTest() {
		Arrangement arrangement = new Arrangement(new String[] { "1", "2", "3", "4" });
		List<String[]> list = arrangement.select(2);
		assertEquals(Arrangement.count(4, 2), list.size());
		assertArrayEquals(new String[] {"1", "2"}, list.get(0));
		assertArrayEquals(new String[] {"1", "3"}, list.get(1));
		assertArrayEquals(new String[] {"1", "4"}, list.get(2));
		assertArrayEquals(new String[] {"2", "1"}, list.get(3));
		assertArrayEquals(new String[] {"2", "3"}, list.get(4));
		assertArrayEquals(new String[] {"2", "4"}, list.get(5));
		assertArrayEquals(new String[] {"3", "1"}, list.get(6));
		assertArrayEquals(new String[] {"3", "2"}, list.get(7));
		assertArrayEquals(new String[] {"3", "4"}, list.get(8));
		assertArrayEquals(new String[] {"4", "1"}, list.get(9));
		assertArrayEquals(new String[] {"4", "2"}, list.get(10));
		assertArrayEquals(new String[] {"4", "3"}, list.get(11));

		List<String[]> selectAll = arrangement.selectAll();
		assertEquals(Arrangement.countAll(4), selectAll.size());

		List<String[]> list2 = arrangement.select(0);
		assertEquals(1, list2.size());
	}