@Override
    public String toString() {
        final String nInfo = n == 1 ? "" : "(" + n + ")";
        return getClass().getSimpleName() + nInfo + "[" + this.indicator + "]";
    }
@Test
    public void testToStringMethodWithNGreaterThen1() {
        prevValueIndicator = new PreviousValueIndicator(openPriceIndicator, 2);

        final String prevValueIndicatorAsString = prevValueIndicator.toString();

        assertTrue(prevValueIndicatorAsString.startsWith("PreviousValueIndicator(2)["));
        assertTrue(prevValueIndicatorAsString.endsWith("]"));
    }