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