'宣言
Public Interface IGroupingBuilder (Of TKey,TGrouping As IGrouping(Of TKey))
public interface IGroupingBuilder<TKey,TGrouping> where TGrouping: IGrouping<TKey>
'宣言
Public Interface IGroupingBuilder (Of TKey,TGrouping As IGrouping(Of TKey))
public interface IGroupingBuilder<TKey,TGrouping> where TGrouping: IGrouping<TKey>