}
// init aggregationClasses
aggregationClasses = (Class<? extends UDAF>[]) new Class[conf.getAggregators().size()];
for (int i = 0; i < conf.getAggregators().size(); i++) {
aggregationDesc agg = conf.getAggregators().get(i);
aggregationClasses[i] = agg.getAggregationClass();
}
// init aggregations, aggregationsAggregateMethods,
// aggregationsEvaluateMethods
aggregationsAggregateMethods = new Method[aggregationClasses.length];