@Test
public void testCompareTo() {

  byte[] a = Bytes.toBytes("a");
  byte[] b = Bytes.toBytes("b");
  Column columnA = new Column(a, b);
  Column columnB = new Column(a, b);
  Assert.assertEquals(0, columnA.compareTo(columnB));
  columnA = new Column(a, a);
  columnB = new Column(a, b);
  Assert.assertEquals(-1, columnA.compareTo(columnB));
  columnA = new Column(a, b);
  columnB = new Column(b, a);
  Assert.assertEquals(-1, columnA.compareTo(columnB));
  columnA = new Column(a, b);
  columnB = new Column(a, a);
  Assert.assertEquals(1, columnA.compareTo(columnB));
  columnA = new Column(b, a);
  columnB = new Column(a, b);
  Assert.assertEquals(1, columnA.compareTo(columnB));
}