@Test
public void calculatesOpposite() {

    final Vect<Double> vecta = new FixedVector<>(
        new Scalars<>(1 + new Random().nextInt(OppositeTest.COORDS_LENGTH))
    );
    final Scalar<Double>[] sum = new Sum<>(
        new Opposite<>(vecta), vecta
    ).coords();
    final Decimal field = new Decimal();
    for (final Scalar<Double> scalar : sum) {
        MatcherAssert.assertThat(field.actual(scalar), Matchers.is(0.));
    }
}