public void RefType_AsSuccessfulOpResOfBaseType_SuccessfulOperationResultOf()
        {
            //Arrange
            var value = new TestInterfaceImpl(4);

            //Act
            OperationResultOf <ITestInterface> opRes =
                value.AsSuccessfulOpRes <ITestInterface>();

            //Assert
            Assert.IsTrue(opRes.Success);
            Assert.IsNull(opRes.ErrorMessage);
            Assert.AreEqual(value, opRes.Value);
        }