'宣言 Public Overrides Function Sum( _ ByVal value1 As Nullable(Of Decimal), _ ByVal value2 As Nullable(Of Decimal) _ ) As Nullable(Of Decimal)
public override Nullable<decimal> Sum( Nullable<decimal> value1, Nullable<decimal> value2 )
NullableDecimalAverageAggregator クラス NullableDecimalAverageAggregator メンバ