public void ShouldReturnNull_WhenInvalidInputDate()
        {
            var result = new Peter.Models.Builders.MarketDataEntityBuilder()
                         .SetClosingPrice(1.7m)
                         .SetName("Ok")
                         .Build();

            result.Should().BeNull();
        }
        [TestCase(1, "\n")]  // whitespace name
        public void ShouldReturnNull_WhenInvalidInput(decimal closingPrice, string name)
        {
            DateTime dateTime = new DateTime(2999, 12, 31);

            var result = new Peter.Models.Builders.MarketDataEntityBuilder()
                         .SetClosingPrice(closingPrice)
                         .SetDateTime(dateTime)
                         .SetName(name)
                         .Build();

            result.Should().BeNull();
        }