错误-电子邮件地址格式不正确。Xcode Swift Firebase

func isValidEmail(email: String) -> Bool {
    let emailRegex = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}"
    let emailPredicate = NSPredicate(format: "SELF MATCHES %@", emailRegex)
    return emailPredicate.evaluate(with: email)
}

let email = "example@example.com"
if isValidEmail(email: email) {
    print("电子邮件地址格式正确")
} else {
    print("电子邮件地址格式不正确")
}

import Firebase

let email = "example@example.com"
Auth.auth().fetchSignInMethods(forEmail: email) { (methods, error) in
    if let error = error {
        print("验证电子邮件地址出错：\(error.localizedDescription)")
    } else if methods != nil {
        print("电子邮件地址格式正确")
    } else {
        print("电子邮件地址格式不正确")
    }
}