Test for Superman in Swift 2

SuperManIdentityTest.swift

enum SuperManIdentityError: ErrorType {
    case WrongSecretIdentityError
}

func isSuperManTest(testWithSecretIdentity secretIdentity: String) throws -> String {
    if secretIdentity != "Clark Kent" {
        throw SuperManIdentityError.WrongSecretIdentityError
    }
    return secretIdentity
}

do {
    let secretIdentityTest = try isSuperManTest(testWithSecretIdentity: "Bruce Wayne")
} catch let error {
    print("Wrong secret identity")
}