Calculator { public Calculator subtract(double value) { state -= value; return this; }  Calculator add(double value); Calculator subtract(double value); Calculator multiply(double value); Calculator divide(double value); Calculator divideWithException(double value); void resetCalc(); double value();  }
@Test(groups = { "test", "broken" }) public void testSubtract() { calculator.subtract(5); assertThat(calculator.value(), equalTo(-5.0)); }