public StringifiedAccumulatorResult[] getAggregatedUserAccumulatorsStringified() { Map<String, Accumulator<?, ?>> userAccumulators = new HashMap<String, Accumulator<?, ?>>(); for (ExecutionVertex vertex : taskVertices) { Map<String, Accumulator<?, ?>> next = vertex.getCurrentExecutionAttempt().getUserAccumulators(); if (next != null) { AccumulatorHelper.mergeInto(userAccumulators, next); } } return StringifiedAccumulatorResult.stringifyAccumulatorResults(userAccumulators); }