@Test
public void testToString() {

  Pair<String, Integer> p1 = new Pair<String, Integer>("a", 123123);
  assertEquals("<a,123123>", p1.toString());
  Pair<Float, Double> p2 = new Pair<Float, Double>(32.5f, 123.123d);
  assertEquals("<32.5,123.123>", p2.toString());
}