assertEquals(2, array.length);
assertEquals(1.0, array[0][0], EPSILON);
assertEquals(2.0, array[1][0], EPSILON);
s.add(2.0, null);
array = s.toArray();
assertEquals(2, array.length);
assertEquals(2, array[0].length);
assertEquals(2, array[1].length);
assertEquals(2.0, array[0][1], EPSILON);
assertTrue(Double.isNaN(array[1][1]));