Swift 3 Eureka验证UILabels出现错误

import Eureka

let requiredField = LabelRow() {
    $0.title = "Required Field"
    $0.placeholder = "Enter text here"
}.cellSetup { cell, row in
    // 设置验证器
    row.add(rule: RuleRequired(msg: "This field is required."))
}.onChange { row in
    // 处理变化
}

form +++ Section("Section Title")
    <<< LabelRow() {
        $0.title = "Field Title"
        $0.placeholder = "Enter text here"
    }.onCellHighlightChanged { cell, row in
        // 当单元格高亮改变时，手动验证
        row.validate()
    }

import UIKit
import Eureka

class ViewController: FormViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        form +++ Section("Personal Details")
            <<< LabelRow() {
                $0.title = "Name"
                $0.placeholder = "Enter your name"
            }.cellSetup { cell, row in
                row.add(rule: RuleRequired(msg: "Name is required."))
            }.onChange { row in
                row.validate()
            }
    }
}