PivotData Class

public class PivotData : IPivotData, IEnumerable<KeyValuePair<Object[], IAggregator>>, 
	IEnumerable

Public Class PivotData
	Implements IPivotData, IEnumerable(Of KeyValuePair(Of Object(), IAggregator)), 
	IEnumerable

public ref class PivotData : IPivotData, 
	IEnumerable<KeyValuePair<array<Object^>^, IAggregator^>>, 
	IEnumerable

type PivotData =  
    class
        interface IPivotData
        interface IEnumerable<KeyValuePair<Object[], IAggregator>>
        interface IEnumerable
    end

DataTable dataTbl; // lets assume it has columns: 'Delivery Year', 'Delivery Month', 'Supplier Name'
            var pvtData = new PivotData(
                new []{"Delivery Year", "Delivery Month", "Supplier Name"},
                new CountAggregatorFactory(), true);
            pvtData.ProcessData( new DataTableReader(dataTbl) );  // real ADO.NET data reader can be used too

var pvtData = new PivotData(
                new string[]{"country","product"},
                new CompositeAggregatorFactory(
                    new CountAggregatorFactory(),
                    new SumAggregatorFactory("amount")
                ), true );

var compositeAggr = pvtData["USA",null].AsComposite();
            var countValue = compositeAggr.Aggregators[0].Value; // refers to CountAggregator
            var sumValue = compositeAggr.Aggregators[1].Value; // refers to SumAggregator