@Test
public void mergeWithEmpty() {
HiveConf conf = new HiveConf();
int avgRowSize = 100;
int r0 = 13;
int r1 = 15;
int deserFactor = (int) conf.getFloatVar(ConfVars.HIVE_STATS_DESERIALIZATION_FACTOR);
Partish p0 = new LocalPartishBuilder().numRows(r0).rawDataSize(avgRowSize * r0).buildPartition();
Partish p1 = new LocalPartishBuilder().totalSize(r1 * avgRowSize / deserFactor).buildPartition();
BasicStats.Factory factory =
new BasicStats.Factory(new BasicStats.DataSizeEstimator(conf), new BasicStats.RowNumEstimator(avgRowSize));
BasicStats bs0 = factory.build(p0);
BasicStats bs1 = factory.build(p1);
BasicStats res = BasicStats.buildFrom(Lists.newArrayList(bs0, bs1));
assertEquals(r0 + r1, res.getNumRows());
assertEquals(avgRowSize * (r0 + r1), res.getDataSize());
}