public void ParseInput_InCorrectDateArgs_ReturnsException(string inputArgument)
 {
     Assert.Throws <FormatException>(() => RangeCalculatorProgram.ParseInput(inputArgument));
 }
        public void ParseInput_CorrectDateArgs_ReturnsParsedDate(string inputArgument)
        {
            var result = RangeCalculatorProgram.ParseInput(inputArgument);

            Assert.IsInstanceOf <DateTime>(result);
        }