Conditional binding cascade rule does not work

[BoonMap]

Dear team,

Below is my sample code

// MARK: Condition binding cascade rule
func conditionBindingCascade() -> Void {
let a: String? = "a"
let b: String? = "b"

    // Preffered
    if let a = a, b = b {
        debugPrint("Preffered \(a),\(b)")
    }

    // Not preffered
    if let c = a, let d = b {
        debugPrint("Not preffered \(c),\(d)")
    }
}

And it is not warned. This rule has enabled, I'd checked in command line with "swiftlint rules" command.