### Question:
BondOrderDifference implements IDifference { @Override public String toString() { return name + ":" + (first == null ? "NA" : first) + "/" + (second == null ? "NA" : second); } private  BondOrderDifference(String name, IBond.Order first, IBond.Order second); static IDifference construct(String name, IBond.Order first, IBond.Order second); @Override String toString();  }### Answer:
@Test public void testToString() { IDifference result = BondOrderDifference.construct("Foo", null, IBond.Order.SINGLE); String diffString = result.toString(); Assert.assertNotNull(diffString); assertOneLiner(diffString); }