如何在视图控制器单元测试中测试设置私有变量的方法？

import XCTest

class MyViewControllerTests: XCTestCase {
    func testSetPrivateVariable() {
        let myViewController = MyViewController()
        
        let mirror = Mirror(reflecting: myViewController)
        for child in mirror.children {
            if child.label == "privateVariable" {
                if let value = child.value as? String {
                    XCTAssertEqual(value, "initialValue")
                    
                    // 设置私有变量的新值
                    myViewController.setValue("newValue", forKey: child.label!)
                    
                    XCTAssertEqual(myViewController.privateVariable, "newValue")
                }
            }
        }
    }
}