PairTradeRoundTripBuilder implements IRoundTripBuilder { @Override public IRoundTrip buildRoundTrip() { return new PairTradeRoundTrip(); }  @Override IRoundTrip buildRoundTrip();  }
@Test public void testBuildRoundTrip() { PairTradeRoundTripBuilder builder = new PairTradeRoundTripBuilder(); IRoundTrip roundTrip = builder.buildRoundTrip(); assertTrue( roundTrip instanceof PairTradeRoundTrip ); }