public void resetEvaluators() {
    for (VectorPTFEvaluatorBase evaluator : evaluators) {
      evaluator.resetEvaluator();
      evaluator.onPartitionEnd();
    }
  }
Buffers a batch at the end of bufferedBatches, and if it's full, spills a block of batches to
the disk.

@param batch
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/ptf/VectorPTFGroupBatches.java