@Test
public void lag() {

  fillLargerColumn();
  TimeColumn column2 = column1.lag(2);
  Table t = Table.create("t");
  t.addColumns(column1, column2);
  for (int i = 0; i < column1.size() - 2; i++) {
    assertEquals(column2.getIntInternal(i + 2), column1.getIntInternal(i));
  }
}