for (AggregatorWithName<?> aggWithName : taskConfig.getIterationAggregators(getUserCodeClassLoader())) {
aggregators.put(aggWithName.getName(), aggWithName.getAggregator());
}
// store the aggregator convergence criterion
if (taskConfig.usesConvergenceCriterion()) {
convergenceCriterion = taskConfig.getConvergenceCriterion(getUserCodeClassLoader());
convergenceAggregatorName = taskConfig.getConvergenceCriterionAggregatorName();
Preconditions.checkNotNull(convergenceAggregatorName);
}