public void ToString_ThrowsException_ForInvalidAmount([NotNull] string amount)
        {
            // Arrange
            var sut = new DollarsCentsToLongConverter();

            // Act
            // Assert
            Assert.Throws <ArgumentException>(() => sut.Convert(amount));
        }
        public void ToString_SetsDollars_ForValidAmount([NotNull] string amount,
                                                        int expected)
        {
            // Arrange
            var sut = new DollarsCentsToLongConverter();

            // Act
            sut.Convert(amount);

            // Assert
            Assert.AreEqual(expected,
                            sut.Dollars);
        }