### Question:
DecimalColumnStatsMerger extends ColumnStatsMerger { public void setLowValue(DecimalColumnStatsDataInspector aggregateData, DecimalColumnStatsDataInspector newData) { final Decimal aggregateLowValue = aggregateData.getLowValue(); final Decimal newLowValue = newData.getLowValue(); final Decimal mergedLowValue; if (!aggregateData.isSetLowValue() && !newData.isSetLowValue()) { return; } else if (aggregateData.isSetLowValue() && newData.isSetLowValue()) { mergedLowValue = ObjectUtils.min(newLowValue, aggregateLowValue); } else { mergedLowValue = MoreObjects.firstNonNull(aggregateLowValue, newLowValue); } aggregateData.setLowValue(mergedLowValue); }  @Override void merge(ColumnStatisticsObj aggregateColStats, ColumnStatisticsObj newColStats); void setLowValue(DecimalColumnStatsDataInspector aggregateData, DecimalColumnStatsDataInspector newData); void setHighValue(DecimalColumnStatsDataInspector aggregateData, DecimalColumnStatsDataInspector newData);  }### Answer:
@Test public void testCompareSimpleReversed() { DecimalColumnStatsDataInspector data1 = new DecimalColumnStatsDataInspector(DATA_3); DecimalColumnStatsDataInspector data2 = new DecimalColumnStatsDataInspector(DATA_5); merger.setLowValue(data1, data2); Assert.assertEquals(DECIMAL_3, data1.getLowValue()); }
@Test public void testCompareSimpleFlippedReversed() { DecimalColumnStatsDataInspector data1 = new DecimalColumnStatsDataInspector(DATA_5); DecimalColumnStatsDataInspector data2 = new DecimalColumnStatsDataInspector(DATA_3); merger.setLowValue(data1, data2); Assert.assertEquals(DECIMAL_3, data1.getLowValue()); }
@Test public void testCompareNullsMin() { DecimalColumnStatsDataInspector data1 = new DecimalColumnStatsDataInspector(); DecimalColumnStatsDataInspector data2 = new DecimalColumnStatsDataInspector(); merger.setLowValue(data1, data2); Assert.assertNull(data1.getLowValue()); }
@Test public void testCompareFirstNullMin() { DecimalColumnStatsDataInspector data1 = new DecimalColumnStatsDataInspector(); DecimalColumnStatsDataInspector data2 = new DecimalColumnStatsDataInspector(DATA_3); merger.setLowValue(data1, data2); Assert.assertEquals(DECIMAL_3, data1.getLowValue()); }
@Test public void testCompareSecondNullMin() { DecimalColumnStatsDataInspector data1 = new DecimalColumnStatsDataInspector(DATA_3); DecimalColumnStatsDataInspector data2 = new DecimalColumnStatsDataInspector(); merger.setLowValue(data1, data2); Assert.assertEquals(DECIMAL_3, data1.getLowValue()); }