In cases where "getResult" contains a statistical calculation, it now checks if the internal state of the underlying statistic has changed and only recalculates if this is true. this way muliple calls to getResult when the staistic has not been incremented are less expensive because it is only returning a property value.
jakarta/commons/proper/math/trunk/src/java/org/apache/commons/math/stat/univariate/AbstractStorelessUnivariateStatistic.java