private static IntegerColumnStatistics deserializeIntColumnStatistics(List<OrcProto.ColumnStatistics> colStats, int id) {
    return (IntegerColumnStatistics) ColumnStatisticsImpl.deserialize(null, colStats.get(id));
  }
@return how many delete events are actually loaded
ql/src/java/org/apache/hadoop/hive/ql/io/orc/VectorizedOrcAcidRowBatchReader.java