public NumericIndicator minus(Indicator<Num> other) {
        return NumericIndicator.of(BinaryOperation.difference(this, other));
    }
@Test
    public void minus() {
        final NumericIndicator numericIndicator = NumericIndicator.of(cp1);

        final NumericIndicator staticOp = numericIndicator.minus(5);
        assertNumEquals(1 - 5, staticOp.getValue(0));
        assertNumEquals(9 - 5, staticOp.getValue(8));

        final NumericIndicator dynamicOp = numericIndicator.minus(ema);
        assertNumEquals(cp1.getValue(0).minus(ema.getValue(0)), dynamicOp.getValue(0));
        assertNumEquals(cp1.getValue(8).minus(ema.getValue(8)), dynamicOp.getValue(8));
    }