如何使用Swift 3.0检查Facebook访问令牌是否有效？

import Foundation
import UIKit
import FBSDKCoreKit
import FBSDKLoginKit

func checkAccessTokenValidity(accessToken: String) -> Bool {
    let graphRequest = FBSDKGraphRequest(graphPath: "/me", parameters: ["fields": "id"])
    graphRequest.start { (connection, result, error) in
        if let error = error {
            print("Error: \(error.localizedDescription)")
            return false
        }
        
        if let result = result as? [String: Any], let _ = result["id"] {
            return true
        } else {
            return false
        }
    }
}

// 使用示例
let accessToken = "YOUR_ACCESS_TOKEN"
let isValid = checkAccessTokenValidity(accessToken: accessToken)
print("Access Token is valid: \(isValid)")