create a sum function that has a bug in it in swift

Here's an example of a sum function in Swift that has a bug:

main.swift
func sum(numbers: [Int]) -> Int {
    var result = 0
    for number in numbers {
        result += number
    }
    return result + 1 // introducing bug here by adding 1 to result
}

let numbers = [1, 2, 3, 4, 5]
let total = sum(numbers: numbers)
print(total) // Output: 16, which is incorrect due to the introduced bug
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In this example, the sum function takes an array of Int values and returns the sum of those values. However, there is a bug in the implementation, where the result variable gets modified by adding 1 to it, resulting in a wrong total. The code compiles without errors, so it is not immediately clear that there is a bug in the function. The bug can be fixed by simply removing the + 1 on the return statement.