@Test
public SparseVector empty() {
SparseVector v = new SparseVector(10, 3);
assertEquals(10, v.size());
assertEquals(0, v.used());
assertEquals(0, v.get(0), Double.MIN_VALUE);
assertEquals(0, v.get(1), Double.MIN_VALUE);
assertEquals(0, v.get(2), Double.MIN_VALUE);
assertEquals(0, v.get(3), Double.MIN_VALUE);
assertEquals(0, v.get(4), Double.MIN_VALUE);