[<Fact>]
let ``should return sum of input keeping in mind that we have a custom delimiter``() =
    let test (dataInput: int[], delimiter: NonEmptyString) =
        let expectedResult = arraySum(dataInput)
        let input = createInput(dataInput, delimiter.Get)
        let result = (new Calculator()).Add(delimiter.Get, input)
        (result = expectedResult)
            .When(isNotInt(delimiter.Get) = true)
            .Label(sprintf "Expected sum of input values: %d but instead gets %d, value passed to a method: %s and a delimiter: %s" expectedResult result input delimiter.Get)
    Check.QuickThrowOnFailure test