if(distinctFieldData == null && sliceFieldData == null)
if(valueFieldData == null)
_collector = new CountingCollector<NullFieldData>(keyFieldData, tzRounding);
else
_collector = new CountingCollector(keyFieldData, valueFieldData, tzRounding);
else if(distinctFieldData == null)
if(valueFieldData == null)
_collector = new SlicedCollector(keyFieldData, sliceFieldData, tzRounding);
else
_collector = new SlicedCollector(keyFieldData, valueFieldData, sliceFieldData, tzRounding);